CN219676399U - Electro-optic modulator - Google Patents

Abstract

There is provided an electro-optic modulator comprising a waveguide layer and an electrode layer, the electrode layer comprising: a plurality of first sub-electrodes arranged in sequence and a plurality of first connection electrodes correspondingly connected with the plurality of first sub-electrodes; a plurality of second sub-electrodes arranged in sequence and a plurality of second connection electrodes correspondingly connected with the plurality of second sub-electrodes; a plurality of third sub-electrodes arranged in sequence and a plurality of third connection electrodes correspondingly connected with the plurality of third sub-electrodes; and a plurality of fourth sub-electrodes and a plurality of fourth connection electrodes correspondingly connected to the plurality of fourth sub-electrodes, which are sequentially arranged; the first sub-electrodes and the fourth sub-electrodes are grounded, the second sub-electrodes and the third sub-electrodes receive differential signals, the first sub-electrodes and the second sub-electrodes form a first electric field, and the third sub-electrodes and the fourth sub-electrodes form a second electric field opposite to the first electric field; the waveguide layer includes a first waveguide arm positioned in a first electric field and a second waveguide arm positioned in a second electric field.

Description

Electro-optic modulator

Technical Field

The present disclosure relates to the field of optical communications technologies, and in particular, to an electro-optical modulator.

Background

In recent years, with the rapid development of the network application services such as internet of things, unmanned operation, telemedicine, and distance education, higher requirements are being put on high-speed high-capacity communication technologies. Optical communication has been rapidly developed in the high-speed and high-capacity communication direction due to the characteristics of large bandwidth, high reliability, low cost, strong anti-interference capability and the like. How to load high-speed electrical signals onto an optical carrier is a core research.

An Electro-optic modulator is a modulator made based on the Electro-optic effect of Electro-optic materials. The electro-optical effect is that when a voltage is applied to an electro-optical material such as a lithium niobate crystal, a gallium arsenide crystal, or a lithium tantalate crystal, the refractive index of the electro-optical material changes, and the characteristics of light waves passing through the electro-optical material change. The modulation of parameters such as phase, amplitude, intensity and polarization state of the optical signal can be realized by utilizing the electro-optical effect.

With the increasing demand for high-speed, high-capacity communication technologies, there is a growing demand for low-loss and operational performance of electro-optic modulators.

Disclosure of Invention

Embodiments of the present disclosure provide an electro-optic modulator to reduce transmission loss and improve operational performance of the electro-optic modulator.

The electro-optic modulator provided by the embodiment of the disclosure comprises a substrate, an isolation layer, a waveguide layer and an electrode layer which are sequentially arranged, wherein the electrode layer comprises: a plurality of first sub-electrodes arranged in sequence along a first direction and a plurality of first connection electrodes cross-connected in one-to-one correspondence with the plurality of first sub-electrodes; a plurality of second sub-electrodes arranged in sequence along the first direction and a plurality of second connection electrodes which are in one-to-one correspondence and are in cross connection with the plurality of second sub-electrodes; a plurality of third sub-electrodes arranged in sequence along the first direction and a plurality of third connection electrodes cross-connected in a one-to-one correspondence with the plurality of third sub-electrodes; and a plurality of fourth sub-electrodes and a plurality of fourth connection electrodes, which are cross-connected to the plurality of fourth sub-electrodes in one-to-one correspondence, sequentially arranged along the first direction; the first sub-electrodes and the fourth sub-electrodes are configured to be grounded, the second sub-electrodes and the third sub-electrodes are configured to receive differential signals, a first electric field is formed between the first sub-electrodes and the second sub-electrodes, and a second electric field opposite to the first electric field is formed between the third sub-electrodes and the fourth sub-electrodes; the waveguide layer includes a first waveguide arm and a second waveguide arm, the first waveguide arm being located between and not intersecting the plurality of first connection electrodes and the plurality of second connection electrodes in a direction perpendicular to the substrate, the second waveguide arm being located between and intersecting the plurality of third connection electrodes and the plurality of fourth connection electrodes.

In some embodiments, the electrode layer comprises a first ground electrode, a first signal electrode, a second signal electrode, and a second ground electrode disposed in sequence, the first signal electrode and the second signal electrode configured to receive a differential signal, wherein: the first ground electrode comprises a first main electrode, a plurality of first connecting electrodes connected with the first main electrode, and a plurality of first sub-electrodes; the first signal electrode comprises a second main electrode, a plurality of second connecting electrodes connected with the second main electrode and a plurality of second sub-electrodes; the second signal electrode comprises a third main electrode, a plurality of third connecting electrodes connected with the third main electrode and a plurality of third sub-electrodes; the second ground electrode includes a fourth main electrode, a plurality of fourth connection electrodes connected to the fourth main electrode, and a plurality of fourth sub-electrodes.

In some embodiments, the second and third main electrodes are spaced from the substrate by a distance h1 and the first and fourth main electrodes are spaced from the substrate by a distance h2, wherein h1+noter2.

In some embodiments, the first main electrode, the second main electrode, the third main electrode, and the fourth main electrode are folded as a whole and do not intersect each other; the first waveguide arm and the second waveguide arm do not cross the first main electrode, the second main electrode, the third main electrode and the fourth main electrode; alternatively, at least one of the first waveguide arm and the second waveguide arm intersects one or more of the first main electrode, the second main electrode, the third main electrode, and the fourth main electrode.

In some embodiments, the electrode layer further comprises: and a third ground electrode positioned between the first signal electrode and the second signal electrode.

In some embodiments, the first main electrode, the second main electrode, the third ground electrode, the third main electrode, and the fourth main electrode are folded as a whole and do not intersect each other; the first waveguide arm and the second waveguide arm do not intersect the first main electrode, the second main electrode, the third ground electrode, the third main electrode, and the fourth main electrode; alternatively, at least one of the first waveguide arm and the second waveguide arm intersects one or more of the first main electrode, the second main electrode, the third ground electrode, the third main electrode, and the fourth main electrode.

In some embodiments, the electrode layer includes a first ground electrode, a first signal electrode, a second ground electrode, a second signal electrode, and a third ground electrode disposed in sequence, the first signal electrode and the second signal electrode configured to receive a differential signal, wherein: the second ground electrode includes: a first main electrode, a plurality of first connection electrodes and a plurality of first sub-electrodes positioned at one side of the first main electrode and connected to the first main electrode, and a plurality of fourth connection electrodes and a plurality of fourth sub-electrodes positioned at the other side of the first main electrode and connected to the first main electrode; the first signal electrode comprises a second main electrode, a plurality of second connecting electrodes connected with the second main electrode and a plurality of second sub-electrodes; the second signal electrode includes a third main electrode, a plurality of third connection electrodes connected to the third main electrode, and a plurality of third sub-electrodes.

In some embodiments, the second and third main electrodes are spaced from the substrate by a distance h3, and the first, third and first main electrodes are spaced from the substrate by a distance h4, where h3+noteq.h4.

In some embodiments, the first, second, first, third, and third ground electrodes are folded as a whole and do not intersect each other; the first waveguide arm and the second waveguide arm do not cross with the first ground electrode, the second main electrode, the first main electrode, the third main electrode and the third ground electrode; alternatively, at least one of the first waveguide arm and the second waveguide arm intersects one or more of the first ground electrode, the second main electrode, the first main electrode, the third main electrode, and the third ground electrode.

In some embodiments, each first sub-electrode is connected to a corresponding first connection electrode in a T-shape or L-shape; each second sub-electrode is connected with the corresponding second connecting electrode in a T shape or an L shape; each third sub-electrode is connected with the corresponding third connecting electrode in a T shape or an L shape; each fourth sub-electrode is connected with the corresponding fourth connecting electrode in a T shape or an L shape.

In some embodiments, the plurality of first sub-electrodes and the plurality of second sub-electrodes are disposed opposite one another in a one-to-one correspondence along the first direction, and the plurality of third sub-electrodes and the plurality of fourth sub-electrodes are alternately disposed.

In some embodiments, the waveguide layer further comprises: the first waveguide arm and the second waveguide arm are positioned on one side of the slab waveguide away from the substrate.

In some embodiments, the electro-optic modulator further comprises: the optical splitting element comprises a signal input end, a first optical splitting output end and a second optical splitting output end, wherein one ends of the first waveguide arm and the second waveguide arm are connected with the first optical splitting output end and the second optical splitting output end in a one-to-one correspondence manner; and the light combining element comprises a first light splitting input end, a second light splitting input end and a signal output end, wherein the other ends of the first waveguide arm and the second waveguide arm are connected with the first light splitting input end and the second light splitting input end in a one-to-one correspondence manner.

According to one or more embodiments of the present disclosure, the structural design of the electrode layer may not only realize the reverse design of the electric field acting on the two waveguide arms, but also shorten the interval between the signal electrode and the ground electrode, so that the electric field strength may be improved and the transmission loss of the electric signal may be reduced.

These and other aspects of the disclosure will be apparent from and elucidated with reference to the embodiments described hereinafter.

Drawings

Further details, features and advantages of the present disclosure are disclosed in the following description of exemplary embodiments, with reference to the following drawings, wherein:

FIG. 1 is a schematic diagram of a conventional electro-optic modulator;

FIG. 2 is a schematic top view of a partial structure of an electro-optic modulator of some embodiments of the present disclosure;

FIG. 3 is a schematic cross-sectional view of an electro-optic modulator of some embodiments of the present disclosure at A-A in FIG. 2;

FIG. 4 is a schematic top view of a partial structure of an electro-optic modulator of some comparative examples of the present disclosure;

FIG. 5 is a schematic top view of a partial structure of an electro-optic modulator of other embodiments of the present disclosure;

FIG. 6 is a schematic cross-sectional view of an electro-optic modulator of further embodiments of the present disclosure at A-A in FIG. 2;

FIG. 7 is a schematic top view of a partial structure of an electro-optic modulator of further embodiments of the present disclosure;

FIG. 8A is a schematic top view of a partial structure of an electro-optic modulator of further embodiments of the present disclosure;

FIG. 8B is a schematic top view of a partial structure of an electro-optic modulator of further embodiments of the present disclosure;

FIG. 9A is a schematic top view of a partial structure of an electro-optic modulator of further embodiments of the present disclosure; and

fig. 9B is a partial structural schematic top view of an electro-optic modulator of further embodiments of the present disclosure.

Reference numerals illustrate:

in the related art:

a 001-Mach-Zehnder modulator; 02-waveguide arm; 01-spectroscopic element; 04-modulating electrode;

040-signal electrode; 041-first ground electrode; 042-a second ground electrode; 05-a light combining element;

in the comparative example of the present disclosure:

002-electro-optic modulator; 241-a first ground electrode; 242-a first signal electrode; 243-a second ground electrode;

244-a second signal electrode; 245-a third ground electrode; 231-a first waveguide arm; 232-a second waveguide arm;

in the embodiments of the present disclosure:

a 100-electro-optic modulator; 110-a substrate; 120-isolating layer; 130-a waveguide layer; 131-a first waveguide arm;

132-a second waveguide arm; 133-slab waveguide; 140 electrode layer; 141-a first ground electrode; 11-a first main electrode;

12-a first connection electrode; 13-a first sub-electrode; 142-a first signal electrode; 21-a second main electrode;

22-a second connection electrode; 23-a second sub-electrode; 143-a second signal electrode; 31-a third main electrode;

32-a third connection electrode; 33-a third sub-electrode; 144-a second ground electrode; 41-a fourth main electrode;

42-fourth connection electrode; 43-fourth sub-electrode; 145-a third ground electrode; 150-patterning the dielectric layer;

741-a first ground electrode; 742-a first signal electrode; 743-a second ground electrode; 744-second signal electrode;

745-a third ground electrode; 7430-a first main electrode; 7420-a second main electrode; 7440-third main electrode.

Detailed Description

Hereinafter, only certain exemplary embodiments are briefly described. As will be recognized by those of skill in the pertinent art, the described embodiments may be modified in various different ways without departing from the spirit or scope of the present disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.

Electro-optic modulation related techniques have been widely developed and used such as optical communications, microwave optoelectronics, laser beam deflection, wavefront modulation, and the like. The Mach-Zehnder Modulator modulator is one type of electro-optical modulator, and equally divides an input optical signal into two branched optical signals, and makes the two branched optical signals enter two waveguide arms respectively, and the two waveguide arms adopt electro-optical materials, and the refractive index of the two waveguide arms changes along with the change of an applied modulation voltage. The change in refractive index of the waveguide arm causes a phase change in the branched optical signals, and therefore, the two branched optical signals are combined and output an interference signal whose intensity varies with the modulation voltage. In short, the mach-zehnder modulator can achieve modulation of different sidebands by controlling the modulation voltages applied to the two waveguide arms. Mach-Zehnder modulators are one of the core devices commonly found in optical interconnects, optical computing, and optical communication systems as devices that convert electrical signals to optical signals.

As shown in fig. 1, a conventional mach-zehnder modulator is schematically shown. In an ideal situation, the two waveguide arms 02 of the mach-zehnder modulator 001 are absolutely identical. When the mach-zehnder modulator 001 is not operating, the electro-optical effect does not occur in both waveguide arms 02, and the input light is equally divided into two branch optical signals after passing through the optical splitter 01, and the phases of the two branch optical signals are still the same after each of the two branch optical signals passes through one waveguide arm 02, so that a coherent reinforcing signal of the two branch optical signals is output from the optical combiner 05. When the mach-zehnder modulator 001 operates, the modulating electrode 04 (including, for example, the signal electrode 040, the first ground electrode 041 and the second ground electrode 042) applies a modulating voltage to the two waveguide arms 02, and after each of the two branched optical signals passes through one waveguide arm 02, the phase of the two branched optical signals may be different by an odd multiple or even multiple of pi, when the phase is different by an even multiple of pi, the optical combining element 05 outputs a coherent reinforcing signal of the two branched optical signals, and when the phase is different by an odd multiple of pi, the optical combining element 05 outputs a coherent cancellation signal of the two branched optical signals.

In electro-optical modulators, the transmission speed of electrical signals is mainly affected by the dielectric constant and structure of the material, and the transmission speed of optical signals is mainly affected by the refractive index and structure of the material. In the electro-optical modulator of the related art, the adopted electro-optical material generally has smaller refractive index and larger dielectric constant, so that the transmission speed of an optical signal is high, the transmission speed of an electric signal is low, the transmission speeds of the two are difficult to match well, the transmission loss of the electro-optical modulator is larger, and the working performance of the device is not ideal.

Based on this, the embodiments of the present disclosure provide an electro-optical modulator that may reduce transmission loss and improve the operation performance of the electro-optical modulator.

As shown in fig. 2 and 3, some embodiments of the present disclosure provide an electro-optic modulator 100 that includes a substrate 110, an isolation layer 120, a waveguide layer 130, and an electrode layer 140, which are disposed in sequence.

In the disclosed embodiment, the electrode layer 140 includes: a plurality of first sub-electrodes 13 arranged in order along the first direction and a plurality of first connection electrodes 12 cross-connected in one-to-one correspondence with the plurality of first sub-electrodes 13; a plurality of second sub-electrodes 23 arranged in order along the first direction and a plurality of second connection electrodes 22 cross-connected to the plurality of second sub-electrodes 23 in one-to-one correspondence; a plurality of third sub-electrodes 33 arranged in order along the first direction and a plurality of third connection electrodes 32 cross-connected in one-to-one correspondence with the plurality of third sub-electrodes 33; and a plurality of fourth sub-electrodes 43 arranged in order along the first direction and a plurality of fourth connection electrodes 42 cross-connected in one-to-one correspondence with the plurality of fourth sub-electrodes 43.

The first sub-electrodes 13 and the fourth sub-electrodes 43 are configured to be grounded, the second sub-electrodes 23 and the third sub-electrodes 33 are configured to receive differential signals (S1 and S2, respectively), a first electric field E1 is formed between the first sub-electrodes 13 and the second sub-electrodes 23, and a second electric field E2 opposite to the first electric field is formed between the third sub-electrodes 33 and the fourth sub-electrodes 43.

The waveguide layer 130 includes a first waveguide arm 131 and a second waveguide arm 132, the first waveguide arm 131 being located between the plurality of first sub-electrodes 13 and the plurality of second sub-electrodes 23 (i.e., in the first electric field E1) and being non-intersecting with the plurality of first connection electrodes 12 and the plurality of second connection electrodes 22 in a direction perpendicular to the substrate 110, and the second waveguide arm 132 being located between the plurality of third sub-electrodes 33 and the plurality of fourth sub-electrodes 43 (i.e., in the second electric field E2) and being intersecting with the plurality of third connection electrodes 32 and the plurality of fourth connection electrodes 42.

In the embodiment shown in fig. 2 and 3, the electrode layer adopts an electrode arrangement design of GSSG (G represents a ground electrode and S represents a signal electrode). The electrode layer 140 includes a first ground electrode 141, a first signal electrode 142, a second signal electrode 143, and a second ground electrode 144, which are sequentially disposed. The first signal electrode 142 and the second signal electrode 143 are configured to receive differential signals. The first ground electrode 141 includes a first main electrode 11, the plurality of first connection electrodes 12 connected to the first main electrode 11, and the plurality of first sub-electrodes 13. The first signal electrode 142 includes a second main electrode 21, the plurality of second connection electrodes 22 connected to the second main electrode 21, and the plurality of second sub-electrodes 23. The second signal electrode 143 includes the third main electrode 31, the plurality of third connection electrodes 32 connected to the third main electrode 31, and the plurality of third sub-electrodes 33. The second ground electrode 144 includes the fourth main electrode 41, the plurality of fourth connection electrodes 42 connected to the fourth main electrode 41, and the plurality of fourth sub-electrodes 43.

The basic structure of the electro-optical modulator 100 generally further includes an optical splitting element and an optical combining element (not shown in the drawing, the connection between the optical splitting element and the first waveguide arm 131 and the second waveguide arm 132 may be referred to as fig. 1), where the optical splitting element includes at least a signal input end, a first optical splitting output end, and a second optical splitting output end, the optical combining element includes at least a first optical splitting input end, a second optical splitting input end, and a signal output end, one ends of the first waveguide arm 131 and the second waveguide arm 132 are connected to the first optical splitting output end and the second optical splitting output end in a one-to-one correspondence, and the other ends of the first waveguide arm 131 and the second waveguide arm 132 are connected to the first optical splitting input end and the second optical splitting input end in a one-to-one correspondence.

In the embodiment of the present disclosure, the first ground electrode 141, the first signal electrode 142, the second signal electrode 143, and the second ground electrode 144 are integrally extended in the first direction, and their respective main electrodes may be disposed in parallel. The first signal electrode 142 and the second signal electrode 143 are configured to receive differential signals, that is, the radio frequency voltage signals S1 and S2 received by the first signal electrode 142 and the second signal electrode 143 are identical in amplitude and opposite in phase (indicated by "-", "+" signs), and the radio frequency voltage signals S1 and S2 are differential signals.

The material of the waveguide layer 130 may include an electro-optic material such as lithium niobate, lithium tantalate, or potassium titanyl phosphate, among others. When differential signals (such as the radio frequency voltage signals S1 and S2 described above) are input to the first and second signal electrodes 142 and 143, and the first and second ground electrodes 141 and 144 are grounded (ground is schematically indicated by "G" in the drawing), the first waveguide arm 131 is positioned in the first electric field E1 formed by the first signal electrode 142 and the first ground electrode 141, and the second waveguide arm 132 is positioned in the second electric field E2 formed by the second signal electrode 143 and the second ground electrode 144, as shown in the drawing, the sub-electrodes of the first and second signal electrodes 141, 142, 143 and the second ground electrode 144 are structured such that the directions of the first and second electric fields E1 and E2 are just opposite. The refractive indexes of the first waveguide arm 131 and the second waveguide arm 132 change with the change of the differential signals S1 and S2 received by the first signal electrode 142 and the second signal electrode 143, so that the phases of the branch optical signals transmitted therein are modulated, and the two branch optical signals obtain a target phase difference when reaching the light combining element, wherein the target phase difference is, for example, odd multiple or even multiple of pi.

In the embodiment of the disclosure, the sub-electrode structural designs of the first ground electrode 141, the first signal electrode 142, the second signal electrode 143 and the second ground electrode 144 not only can realize the reverse design of the first electric field E1 and the second electric field E2, but also can shorten the interval between the signal electrode and the ground electrode to make them approach as much as possible, thereby improving the strength of the electric field and reducing the transmission loss of the electric signal.

In addition, some characteristics (such as impedance, transmission speed, etc.) of the electrode structure are closely related to specific design parameters (such as shape, size, number, etc.) of the sub-electrodes, and the design parameters of the sub-electrodes can be flexibly adjusted according to actual design requirements, so that the impedance of the electro-optical modulator 100 is as same as or similar to the impedance of the input end thereof as possible, the difference of transmission speeds of optical signals and electric signals is compensated to a certain extent, and the transmission speeds of the two signals are matched as much as possible.

As shown in fig. 4, in the electro-optical modulator 002 of some comparative examples of the present disclosure, the electrode layer adopts the electrode arrangement of gsgsgsg, that is, the first ground electrode 241, the first signal electrode 242, the second ground electrode 243, the second signal electrode 244 and the third ground electrode 245 are sequentially disposed, the first ground electrode 241 and the first signal electrode 242 form a first electric field E11, the second ground electrode 243 and the second signal electrode 244 form a second electric field E22 opposite to the first electric field E11, the first waveguide arm 231 is located between the first ground electrode 241 and the first signal electrode 242, and the second waveguide arm 232 is located between the second ground electrode 243 and the second signal electrode 244. In the structure of such an electro-optical modulator 002, in order to shield or reduce crosstalk that may be generated by external factors to the second signal electrode 244, the arrangement of the third ground electrode 245 is also necessary, and therefore, the structural design of the electro-optical modulator 002 includes three ground electrodes, which makes the overall size of the electro-optical modulator 002 in the extending direction perpendicular to the waveguide arm relatively large.

While the design of the electro-optic modulator 100 of the disclosed embodiments, as shown in fig. 2, may include a minimum of two ground electrodes, the overall size of the electro-optic modulator 100 may be designed to be more compact than the comparative examples described above.

In some embodiments of the present disclosure, as shown in fig. 5, the electrode layer 140 may also include a third ground electrode 145 positioned between the first signal electrode 142 and the second signal electrode 143, i.e., an electrode arrangement employing gsgsgsg. In this way, the third ground electrode 145 is located between the first signal electrode 142 and the second signal electrode 143, so that crosstalk that may occur between the two electrodes can be shielded or reduced, thereby improving stability of differential signal transmission, and being beneficial to further reducing transmission loss. The width of the third ground electrode 145 may be designed to be relatively narrow in order to minimize the overall size of the electro-optic modulator 100.

As shown in fig. 2, in some embodiments of the present disclosure, each first sub-electrode 13 is T-connected to the corresponding first connection electrode 12, each second sub-electrode 23 is T-connected to the corresponding second connection electrode 22, each third sub-electrode 33 is T-connected to the corresponding third connection electrode 32, and each fourth sub-electrode 43 is T-connected to the corresponding fourth connection electrode 42.

In other embodiments of the present disclosure, each first sub-electrode may also be connected to a corresponding first connection electrode in an L-shape, and similarly, each second sub-electrode may also be connected to a corresponding second connection electrode in an L-shape, each third sub-electrode may also be connected to a corresponding third connection electrode in an L-shape, and each fourth sub-electrode may also be connected to a corresponding fourth connection electrode in an L-shape.

The shape of the sub-electrode can be flexibly designed according to the actual design requirement, and the design parameters of the sub-electrode can be adjusted, so that the impedance of the electro-optical modulator 100 is the same as or similar to the impedance of the input end of the electro-optical modulator, the transmission speed difference of the optical signal and the electric signal can be compensated as much as possible, and the transmission speeds of the optical signal and the electric signal can be matched as much as possible.

As shown in fig. 2, in some embodiments, along the extending directions (i.e., along the first direction) of the first waveguide arm 131 and the second waveguide arm 132, the plurality of first sub-electrodes 13 are disposed opposite to the plurality of second sub-electrodes 23 in a one-to-one correspondence, and the plurality of third sub-electrodes 33 are disposed alternately with the plurality of fourth sub-electrodes 43. The design can obtain relatively large opposite areas between the plurality of first sub-electrodes 13 and the plurality of second sub-electrodes 23 and between the plurality of third sub-electrodes 33 and the plurality of fourth sub-electrodes 43, so that the intensity of the formed first electric field E1 and second electric field E2 can be improved, and the transmission loss of electric signals can be reduced as much as possible.

In some embodiments of the present disclosure, referring to fig. 6, the distance from the second main electrode 21 and the third main electrode 31 to the substrate 110 is h1, and the distance from the first main electrode 11 and the fourth main electrode 41 to the substrate 110 is h2, where h1+.h2.

The main electrodes of the signal electrodes and the main electrodes of the ground electrodes are arranged at different heights, so that the flexible regulation and control design is conveniently carried out on electric signal transmission by utilizing the height difference through structural design, the difference of optical signal transmission speed and electric signal transmission speed can be reduced, and good matching is realized between the main electrodes and the main electrodes of the ground electrodes.

As shown in fig. 6, in some embodiments of the present disclosure, the electro-optic modulator 100 further comprises: and a patterned dielectric layer 150 between the waveguide layer 130 and the electrode layer 140, the patterned dielectric layer 150 having a dielectric constant smaller than that of the waveguide layer 130, wherein the patterned dielectric layer 150 does not overlap the first main electrode 11 and the fourth main electrode 41 in a direction perpendicular to the substrate 110, and at least a portion of the patterned dielectric layer 150 overlaps the second main electrode 21 and the third main electrode 31. In this embodiment, the second main electrode 21 and the third main electrode 31 are supported to be elevated by using the thickness difference of the patterned dielectric layer 150 in different regions so as to have different set heights from the first main electrode 11 and the fourth main electrode 41.

In other embodiments of the present disclosure, the patterned dielectric layer may also be designed to have no overlap with the second and third main electrodes and at least a portion thereof overlap with the first and fourth main electrodes. In this embodiment, the first main electrode and the fourth main electrode are supported and raised by using the thickness difference of the patterned dielectric layer in different regions, so as to have different set heights from the second main electrode and the third main electrode.

It should be noted that, when the electrode layer of the electro-optical modulator 100 adopts the design shown in fig. 5, the distance from the third ground electrode 145 to the substrate 110 may also be h1, that is, the same height as the first main electrode 11 and the fourth main electrode 41, so as to be different from the arrangement height of the second main electrode 21 and the third main electrode 31.

As shown in fig. 7, in some embodiments of the present disclosure, the electrode layer of the electro-optical modulator 100 adopts an electrode arrangement design of gsgsgsg, and the electrode layer includes a first ground electrode 741, a first signal electrode 742, a second ground electrode 743, a second signal electrode 744, and a third ground electrode 745, which are sequentially disposed. The first signal electrode 742 and the second signal electrode 744 are configured to receive differential signals (illustrated as S1, S2, respectively). The second ground electrode 743 includes a first main electrode 7430, a plurality of first connection electrodes 12 and a plurality of first sub-electrodes 13 positioned at one side of the first main electrode 7430 and connected to the first main electrode 7430, and a plurality of fourth connection electrodes 42 and a plurality of fourth sub-electrodes 43 positioned at the other side of the first main electrode 7430 and connected to the first main electrode 7430. The first signal electrode 742 includes a second main electrode 7420, a plurality of second connection electrodes 22 connected to the second main electrode 7420, and a plurality of second sub-electrodes 23. The second signal electrode 744 includes a third main electrode 7440, a plurality of third connection electrodes 32 connected to the third main electrode 7440, and a plurality of third sub-electrodes 33.

As shown in fig. 7, the first electric field E1 is formed between the plurality of first sub-electrodes 13 and the plurality of second sub-electrodes 23, and the second electric field E2 opposite to the first electric field is formed between the plurality of third sub-electrodes 33 and the plurality of fourth sub-electrodes 43. The first waveguide arm 131 is located between the plurality of first sub-electrodes 13 and the plurality of second sub-electrodes 23 so as to be located in the first electric field E1. The second waveguide arm 132 is located between the plurality of third sub-electrodes 33 and the plurality of fourth sub-electrodes 43 so as to be located in the second electric field E2.

The structural design of the electrode layers in these embodiments not only can realize the reverse design of the first electric field E1 and the second electric field E2, but also can shorten the interval between the signal electrode and the ground electrode, so that the strength of the electric field can be improved and the transmission loss of the electric signal can be reduced.

In some embodiments, the second and third main electrodes 7420, 7440 are spaced from the substrate by a distance h3, and the first, third, and first main electrodes 741, 745, 7430 are spaced from the substrate by a distance h4, where h3+.h4. That is, the main electrodes of the first, third, and second ground electrodes and the main electrodes of the two signal electrodes are arranged at different heights. Therefore, the height difference is convenient to flexibly regulate and control the electric signal transmission through the structural design, and the difference of the transmission speeds of the optical signal and the electric signal can be reduced, so that the optical signal and the electric signal can be well matched.

In the disclosed embodiments, the specific product form of the electro-optic modulator 100 is not limited, and may be designed as a bar-type electro-optic modulator or a folded-type electro-optic modulator based on the concepts described above, for example, wherein the folded-type electro-optic modulator may include one or more bends.

In some embodiments, the electrode layer of the folded electro-optic modulator adopts the electrode arrangement design of GSSG, and the design of each sub-electrode and the connection electrode can refer to the embodiment shown in fig. 2, where the first main electrode 11, the second main electrode 21, the third main electrode 31 and the fourth main electrode 41 are folded (the folded shape is not illustrated) and do not intersect each other.

Based on the GSSG electrode arrangement design, in some embodiments, the first waveguide arm 131, the second waveguide arm 132, the first main electrode 11, the second main electrode 21, the third main electrode 31, and the fourth main electrode 41 are designed to be non-intersecting with each other, and the turns are substantially synchronized.

Based on the GSSG electrode arrangement design, in other embodiments, the first waveguide arm 131 and/or the second waveguide arm 132 may intersect one or more of the first main electrode 11, the second main electrode 21, the third main electrode 31, and the fourth main electrode 41, thereby forming a turn delay. Therefore, the transmission speed of the waveguide and the transmission speed of the electrode can be flexibly adjusted to be matched as much as possible, so that the transmission loss is reduced.

As shown in fig. 8A, in some embodiments of the present disclosure, the electro-optical modulator 100 is a folded electro-optical modulator, and the electrode layer thereof adopts an electrode arrangement design of gsgsgsg, and each sub-electrode and the connection electrode are similar to the embodiment shown in fig. 5, wherein the first main electrode 11, the second main electrode 21, the third ground electrode 145, the third main electrode 31 and the fourth main electrode 41 are folded as a whole and do not cross each other.

In this embodiment, the first waveguide arm 131, the second waveguide arm 132, the first main electrode 11, the second main electrode 21, the third main electrode 31, and the fourth main electrode 41 are designed so as not to intersect each other, and the turns are substantially synchronized.

As shown in fig. 8B, in other embodiments of the present disclosure, the electro-optic modulator 100 is a folded electro-optic modulator, where the electrode layer is configured by using the electrode arrangement of gsgsgsg, and each sub-electrode and the connection electrode are similar to the embodiment shown in fig. 5, where the first main electrode 11, the second main electrode 21, the third ground electrode 145, the third main electrode 31, and the fourth main electrode 41 are folded and do not intersect each other, and the first waveguide arm 131 and the second waveguide arm 132 (which may also be the first waveguide arm 131 or the second waveguide arm 132) intersect one or more of the first main electrode 11, the second main electrode 21, the third ground electrode 145, the third main electrode 31, and the fourth main electrode 41, so as to form a turning delay. Therefore, the transmission speed of the waveguide and the transmission speed of the electrode can be flexibly adjusted to be matched as much as possible, so that the transmission loss is reduced.

As shown in fig. 9A, in some embodiments of the present disclosure, the electro-optic modulator 100 is a folded electro-optic modulator, where the electrode layer is configured by using an electrode arrangement of gsgsgsg, and each sub-electrode and the connection electrode are similar to the embodiment shown in fig. 7, where the first ground electrode 741, the second main electrode 7420, the first main electrode 7430, the third main electrode 7440, and the third ground electrode 745 are folded as a whole and do not intersect each other. In this embodiment, the first waveguide arm 131, the second waveguide arm 132, the first ground electrode 741, the second main electrode 7420, the first main electrode 7430, the third main electrode 7440, and the third ground electrode 745 are designed so as not to intersect each other, and the turning is substantially synchronous.

As shown in fig. 9B, in some embodiments of the present disclosure, the electro-optic modulator 100 is a folded electro-optic modulator, and the electrode layer of the folded electro-optic modulator adopts an electrode arrangement design of gsgsgsg, a part of the sub-electrodes and the connection electrodes are similar to the embodiment shown in fig. 5, and a part of the sub-electrodes and the connection electrodes are similar to the embodiment shown in fig. 7, that is, a combination design of the embodiments shown in fig. 5 and fig. 7 is adopted. The fourth main electrode 41 is connected to the third ground electrode 745 by bending, the third main electrode 31 is connected to the third main electrode 7440 by bending, the third ground electrode 145 is connected to the first main electrode 7430 by bending, the second main electrode 21 is connected to the second main electrode 7420 by bending, and the first main electrode 11 is connected to the first ground electrode 741 by bending. The first waveguide arm 131 and the second waveguide arm 132 (the first waveguide arm 131 or the second waveguide arm 132 may be provided) intersect one or more of the ground electrode or the main electrode, thereby forming a turning delay. Therefore, the transmission speed of the waveguide and the transmission speed of the electrode can be flexibly adjusted to be matched as much as possible, so that the transmission loss is reduced.

The folding type electro-optical modulator is in an S-shaped bending shape, so that the size of the device in the length direction can be reduced. In order to obtain better device performance, the length of the waveguide arm can be increased according to the design requirement, but the folding design is adopted, so that the influence on the length of the device is small, and the miniaturization design of the device can be realized.

As shown in fig. 3, in some embodiments of the present disclosure, the waveguide layer 130 adopts a ridge waveguide design, and further includes a slab waveguide 133, where the first waveguide arm 131 and the second waveguide arm 132 are located on a side of the slab waveguide 133 away from the substrate 110 and integrally connected with the slab waveguide 133, and may be integrally manufactured. The waveguide layer 130 adopts a ridge waveguide design so as to have a series of excellent characteristics of a ridge waveguide, such as a low main mode cut-off frequency, a wide band, and a low impedance.

In summary, the design of the electro-optical modulator 100 according to the above embodiments of the present disclosure not only can realize the reverse design of the electric field acting on the two waveguide arms, but also can shorten the interval between the signal electrode and the ground electrode, so as to improve the electric field strength and reduce the transmission loss of the electric signal.

It should be understood that in this specification, terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., refer to an orientation or positional relationship or dimension based on that shown in the drawings, which are used for convenience of description only, and do not indicate or imply that the device or element referred to must have a particular orientation, be configured and operated in a particular orientation, and thus should not be construed as limiting the scope of protection of the present disclosure.

Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", or a third "may explicitly or implicitly include one or more such feature. In the description of the present disclosure, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present disclosure, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; the device can be mechanically connected, electrically connected and communicated; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the terms in this disclosure will be understood by those of ordinary skill in the art as the case may be.

In this disclosure, unless expressly stated or limited otherwise, a first feature being "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other by way of additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

The specification provides many different embodiments or examples that can be used to implement the present disclosure. It should be understood that these various embodiments or examples are purely illustrative and are not intended to limit the scope of the disclosure in any way. Various changes and substitutions will occur to those skilled in the art based on the disclosure of the specification and these are intended to be included within the scope of the present disclosure. Accordingly, the scope of the present disclosure should be determined by the following claims.

Claims (13)

1. An electro-optic modulator comprising a substrate, an isolation layer, a waveguide layer and an electrode layer arranged in sequence, wherein,

the electrode layer includes: a plurality of first sub-electrodes arranged in sequence along a first direction and a plurality of first connection electrodes cross-connected in one-to-one correspondence with the plurality of first sub-electrodes; a plurality of second sub-electrodes arranged in sequence along the first direction and a plurality of second connection electrodes which are in one-to-one correspondence and are in cross connection with the plurality of second sub-electrodes; a plurality of third sub-electrodes arranged in sequence along the first direction and a plurality of third connection electrodes cross-connected in a one-to-one correspondence with the plurality of third sub-electrodes; and a plurality of fourth sub-electrodes and a plurality of fourth connection electrodes, which are cross-connected to the plurality of fourth sub-electrodes in one-to-one correspondence, sequentially arranged along the first direction; the first sub-electrodes and the fourth sub-electrodes are configured to be grounded, the second sub-electrodes and the third sub-electrodes are configured to receive differential signals, a first electric field is formed between the first sub-electrodes and the second sub-electrodes, and a second electric field opposite to the first electric field is formed between the third sub-electrodes and the fourth sub-electrodes;

The waveguide layer includes a first waveguide arm and a second waveguide arm, the first waveguide arm being located between and non-intersecting the plurality of first connection electrodes and the plurality of second connection electrodes in a direction perpendicular to the substrate, the second waveguide arm being located between and intersecting the plurality of third connection electrodes and the plurality of fourth connection electrodes.

2. An electro-optic modulator according to claim 1 wherein,

the electrode layer comprises a first ground electrode, a first signal electrode, a second signal electrode and a second ground electrode which are sequentially arranged, wherein the first signal electrode and the second signal electrode are configured to receive differential signals, and the differential signals comprise:

the first ground electrode includes a first main electrode, the plurality of first connection electrodes connected to the first main electrode, and the plurality of first sub-electrodes;

the first signal electrode includes a second main electrode, the plurality of second connection electrodes connected to the second main electrode, and the plurality of second sub-electrodes;

the second signal electrode includes a third main electrode, the plurality of third connection electrodes connected to the third main electrode, and the plurality of third sub-electrodes;

The second ground electrode includes a fourth main electrode, the plurality of fourth connection electrodes connected to the fourth main electrode, and the plurality of fourth sub-electrodes.

3. An electro-optic modulator according to claim 2 wherein,

the distance from the second main electrode and the third main electrode to the substrate is h1, and the distance from the first main electrode and the fourth main electrode to the substrate is h2, wherein h1 noteq h2.

4. An electro-optic modulator according to claim 2 wherein,

the first main electrode, the second main electrode, the third main electrode and the fourth main electrode are folded as a whole and do not cross each other;

the first waveguide arm and the second waveguide arm do not cross the first main electrode, the second main electrode, the third main electrode and the fourth main electrode; alternatively, at least one of the first waveguide arm and the second waveguide arm intersects one or more of the first main electrode, the second main electrode, the third main electrode, and the fourth main electrode.

5. An electro-optic modulator according to claim 2 wherein,

the electrode layer further includes: and a third ground electrode positioned between the first signal electrode and the second signal electrode.

6. An electro-optic modulator as defined in claim 5 wherein,

the first main electrode, the second main electrode, the third ground electrode, the third main electrode, and the fourth main electrode are folded as a whole and do not intersect with each other;

the first waveguide arm and the second waveguide arm do not intersect the first main electrode, the second main electrode, the third ground electrode, the third main electrode, and the fourth main electrode; alternatively, at least one of the first waveguide arm and the second waveguide arm intersects one or more of the first main electrode, the second main electrode, the third ground electrode, the third main electrode, and the fourth main electrode.

7. An electro-optic modulator according to claim 1 wherein,

the electrode layer comprises a first ground electrode, a first signal electrode, a second ground electrode, a second signal electrode and a third ground electrode which are sequentially arranged, wherein the first signal electrode and the second signal electrode are configured to receive differential signals, and the differential signals comprise:

the second ground electrode includes: a first main electrode, the plurality of first connection electrodes and the plurality of first sub-electrodes positioned at one side of the first main electrode and connected to the first main electrode, and the plurality of fourth connection electrodes and the plurality of fourth sub-electrodes positioned at the other side of the first main electrode and connected to the first main electrode;

The first signal electrode includes a second main electrode, the plurality of second connection electrodes connected to the second main electrode, and the plurality of second sub-electrodes;

the second signal electrode includes a third main electrode, the plurality of third connection electrodes connected to the third main electrode, and the plurality of third sub-electrodes.

8. An electro-optic modulator as defined in claim 7 wherein,

the distance from the second main electrode and the third main electrode to the substrate is h3, and the distance from the first ground electrode, the third ground electrode and the first main electrode to the substrate is h4, wherein h3 noteq h4.

9. An electro-optic modulator as defined in claim 7 wherein,

the first ground electrode, the second main electrode, the first main electrode, the third main electrode and the third ground electrode are folded as a whole and do not intersect with each other;

the first waveguide arm and the second waveguide arm do not cross with the first ground electrode, the second main electrode, the first main electrode, the third main electrode and the third ground electrode; alternatively, at least one of the first waveguide arm and the second waveguide arm intersects one or more of the first ground electrode, the second main electrode, the first main electrode, the third main electrode, and the third ground electrode.

10. An electro-optic modulator according to any one of claims 1 to 9 wherein,

each first sub-electrode is connected with the corresponding first connecting electrode in a T shape or an L shape;

each second sub-electrode is connected with the corresponding second connecting electrode in a T shape or an L shape;

each third sub-electrode is connected with the corresponding third connecting electrode in a T shape or an L shape;

each fourth sub-electrode is connected with the corresponding fourth connecting electrode in a T shape or an L shape.

11. An electro-optic modulator according to any one of claims 1 to 9 wherein,

along the first direction, the first sub-electrodes and the second sub-electrodes are oppositely arranged in a one-to-one correspondence, and the third sub-electrodes and the fourth sub-electrodes are alternately arranged.

12. An electro-optic modulator according to any one of claims 1 to 9 wherein the waveguide layer further comprises:

and the first waveguide arm and the second waveguide arm are positioned on one side of the slab waveguide away from the substrate.

13. The electro-optic modulator of any of claims 1 to 9, wherein the electro-optic modulator further comprises:

The optical splitting element comprises a signal input end, a first optical splitting output end and a second optical splitting output end, wherein one ends of the first waveguide arm and the second waveguide arm are connected with the first optical splitting output end and the second optical splitting output end in a one-to-one correspondence manner; and

the light combination element comprises a first light splitting input end, a second light splitting input end and a signal output end, wherein the other ends of the first waveguide arm and the second waveguide arm are connected with the first light splitting input end and the second light splitting input end in a one-to-one correspondence mode.