CN215867107U

CN215867107U - Laser radar transmitting and receiving device of optical phased array

Info

Publication number: CN215867107U
Application number: CN202023084292.1U
Authority: CN
Inventors: 张磊
Original assignee: Suzhou Aikrypton Inno Robot Technology Co ltd
Current assignee: Suzhou Aikrypton Inno Robot Technology Co ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2022-02-18
Anticipated expiration: 2030-12-21

Abstract

The utility model provides a laser radar transmitting and receiving device of an optical phased array, which comprises an integrated optical chip, an optical signal isolation device, a 1 XN beam splitter/combiner, a phase control array, an optical antenna, a laser, a photoelectric detector, a signal processing module and a temperature control module. By adopting the device, the transmitting and receiving system of the optical phased array laser radar can adopt the same 1 XN beam splitter/combiner, the same phased array and the same optical antenna, the size of the laser radar can be effectively reduced, the cost is reduced, and the stability is improved.

Description

Laser radar transmitting and receiving device of optical phased array

Technical Field

The utility model relates to the technical field of optical phased arrays, in particular to a laser radar transmitting and receiving device of an optical phased array.

Background

Optical phased array technology comes from microwave phased arrays, which are distinguished by the information carriers used, which in turn makes a great difference in the way they are implemented and the systems. Compared with a microwave phased array, the optical phased array has the advantages that the optical phased array is not interfered by wireless electromagnetic waves due to the fact that the optical wave is used as an information carrier, the laser beam is narrow, the reconnaissance and the confidentiality are not good, and the like. In addition, by means of the existing mature micro-nano processing technology, the optical phased array can be easily integrated on one chip, and the optical phased array has the advantages of small size, light weight, low power consumption and the like. The MEMS-based laser radar has great application prospects in the fields of light detection, distance measurement, laser radar and the like, and particularly has incomparable advantages of the traditional MEMS-based laser radar in the field of laser radar, such as better stability, smaller size, more compact structural layout and the like.

The optical phased array has the basic principle that a beam of light is divided into multiple paths of light signals through a light beam splitter, the phase difference between the light signals is regulated and controlled through a phase shifter array, the equiphase surfaces of the whole light beams output by the signals are further regulated and controlled, the beam coherence satisfying the equiphase relation is long, the beam coherence not satisfying the equiphase condition is cancelled, and when the phases of all the phase modulators satisfy a certain condition, the phase control array can realize the deflection output of the light beams. The emitted light beams are reflected by the object, received by the receiving module and subjected to signal processing to obtain distance or object contour information. Generally, the transmitting and receiving of the laser radar based on the optical phased array are two independent modules, so that the volume size of the laser radar is relatively large, and the cost is high. Patent 201911087564. Although the circulator is also adopted to realize that the laser beam is transmitted and received by sharing the same phase control array, when the circulator is mostly a separating device at present, the circulator is difficult to realize on-chip integration with an adopted integrated optical chip, and the volume of the circulator is still larger, and the device for isolating the transmitting and receiving optical paths adopted by the utility model can be integrated on the same chip with other structures required in a phased array, such as a 1 XN beam splitter/combiner, a phase control array and the like, so that the size of the device can be effectively further reduced.

Disclosure of Invention

In view of the problem that the size of the laser radar transmitting and receiving device is larger due to independence, the utility model provides a laser radar transmitting and receiving device of an optical phased array.

The laser radar transmitting and receiving device of the optical phased array comprises an integrated optical chip, an optical signal isolation device, a 1 XN beam splitter/combiner, a phase control array, an optical antenna, a laser, a photoelectric detector, a signal processing module and a temperature control module.

Furthermore, the frequency response of the signal isolation device, the 1 XN beam splitter/combiner and the optical antenna is matched with the frequency response of the laser and the photoelectric detector.

Further, the beam splitting/combining device at least comprises the following structures: array waveguide grating, directional coupler, Mach-Zehnder interferometer, micro-ring resonator, Y branch, and multi-mode interferometer.

Further, the phase control array controls the phase of the optical signal by applying at least one of the following to the waveguide constituting the phase controller: heat, light, current, voltage, stress.

Further, the refractive index of the integrated optical chip core layer is greater than that of the cladding layer.

Further, the integrated optical chip core material comprises at least one of the following: silicon, silicon nitride, silicon oxynitride, doped silicon dioxide, indium phosphide alloy, gallium arsenide alloy, organic polymer, lithium niobate, lithium carbonate.

Further, the integrated optical chip cladding can be divided into an upper cladding and a lower cladding, and the materials constituting the upper cladding and the lower cladding can be different and at least comprise one of the following materials: silicon dioxide, low refractive index silicon oxynitride, doped silicon dioxide, indium phosphide alloy, gallium arsenide alloy, organic polymer, air.

The device comprises an isolation structure for isolating the optical signal transmitted by the transmitting end from the optical signal received by the receiving end; a 1 xN beam splitting/combining structure, which implements beam splitting of the optical path with respect to the transmitting end, and implements beam combining of the optical path with respect to the receiving end; a phase control array for controlling the phase of N optical signals; an optical antenna for transmitting and receiving optical signals. In the above components, the 1 × N splitting/combining structure is formed by cascading K1 × M splitting/combining devices with J stages, where M is a positive integer greater than or equal to 2, N, J, and K are positive integers, and satisfy:

the 1 xM beam splitter/combiner at the last stage divides the light into N paths, and the N paths are respectively connected with the N optical antenna units. The N optical antennas form a transmitting/receiving structure to realize the transmission and the reception of optical signals.

The working process of the laser radar transmitting and receiving device realized by the utility model is as follows: the light emitting end enters the isolation device, then is divided into N paths of signals through a 1 XN path splitting/combining structure, and respectively enters N phase controllers, and the N paths of signals subjected to phase modulation enter the optical antenna to be emitted outwards at a certain angle. After being reflected by the object, the reflected light enters the phase shifter again through the optical antenna and is combined into 1 path of light through a 1 XN path splitting/combining structure, the combined light enters the photoelectric detector through the isolation device to realize the detection of the optical signal, and the distance or the outline information of the object is provided through necessary signal processing.

Optionally, the transmitting and receiving device based on the optical phased array laser radar is prepared by a mature silicon optical technology by using a silicon-based chip, wherein a waveguide core layer is made of silicon, and an upper cladding layer and a lower cladding layer are made of silicon dioxide;

optionally, the 1 × M beam splitter/combiner forming the beam splitting/combining structure is a 1 × 2 beam splitter/combiner, that is, M is 2;

optionally, the 1 × 2 beam splitter/combiner is implemented by using a multi-mode interferometer (MMI);

optionally, the isolation device adopts a 3dB beam splitter based on a directional coupler to realize on-chip integration;

optionally, the phase shifter adopts a heating electrode to regulate and control the phase of each signal by heating;

optionally, the optical antenna unit adopts grating coupling input and output.

The utility model has the following beneficial effects:

by adopting the device, the transmitting and receiving system of the optical phased array laser radar can adopt the same 1 XN beam splitter/combiner, the same phased array and the same optical antenna, the size of the laser radar can be effectively reduced, the cost is reduced, and the stability is improved.

Drawings

FIG. 1 is a schematic diagram of an optical phased array integrated chip according to an embodiment;

FIG. 2 is a cross-sectional view of a waveguide structure employed in the embodiment;

FIG. 3 is an isolation component for isolating input and output signals based on a directional coupler;

FIG. 4 is a basic 1 × 2 beam splitting/combining unit capable of 1 × N beam splitting/combining structure based on a multimode interferometer (MMI);

FIG. 5 is a schematic diagram of a phase shifter based on thermal modulation;

fig. 6 is an optical antenna unit based on a grating structure.

The optical fiber laser comprises a transmitting laser 100, a transmitting and receiving optical path isolation structure 120, a straight waveguide 121, a straight waveguide 122, a curved waveguide 123, an output end 124, an input end 125, a 1 × N beam splitting/combining structure 130, a basic beam splitting/combining unit 131, a multimode interference region 1311, an input end 1312, an output end 1313, an output end 1314, an N-channel phase control array 140, a phase controller 141, an electrode 1411, an optical antenna 150, a basic unit 151 of the optical antenna, a grating 1511, a silicon-based waveguide 160, a chip 162, an upper cladding 161 and a lower cladding 163.

Detailed Description

To further illustrate the present invention in detail, reference will be made to an embodiment in accordance with the present invention, which is illustrated in the accompanying drawings. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the utility model, as detailed in the appended claims.

Fig. 1 shows a schematic diagram of an embodiment of the present invention, which includes a transmitting laser 100, a transmitting-receiving optical path isolation structure 120, a 1 xn beam splitting/combining structure 130, an N-channel phase control structure 140, and an optical antenna 150. This embodiment is based on silicon optical technology, and a schematic cross-sectional view of a silicon-based waveguide 160 is shown in fig. 2, in which a chip 162 is silicon, an upper cladding 161 and a lower cladding 163 are silicon dioxide, and the width of the silicon waveguide is slightly different according to different structures.

The transmitting and receiving optical path isolation structure 120 adopts a 3dB directional coupler, and is structured as shown in fig. 3, and includes a straight waveguide 121, a straight waveguide 122, and a curved waveguide 123. On-chip integration can be achieved with a 3dB directional coupler structure, but additional 3dB loss is introduced. The basic beam splitting/combining unit 131 of the 1 × N beam splitting/combining structure 130 is based on a 1 × 2 multi-mode interferometer as shown in fig. 4, and includes a multi-mode interference region 1311, an input end 1312, and two output ends 1313, 1314, and the 1 × 2 multi-mode interferometer has the advantages of large process tolerance, simple structure, and the like. The phase controller 141 of the basic unit of the phase control array 140 is implemented by thermal modulation, i.e. heating the silicon waveguide is implemented by preparing the heating electrode 1411 on the phase controller by evaporation or the like. The phase is adjusted and controlled because the refractive index of silicon changes with the change of temperature. The base unit 151 of the optical antenna 150 in the embodiment is implemented by a grating 1511, as shown in fig. 6. The structure of the grating is necessarily optimized according to the wavelength of the optical signal to achieve low-loss transmission and reception.

The working principle of the embodiment is briefly described as follows: the emitting laser 100 is input from an input end 125 through a 3dB directional coupler, and enters a 1 × N splitting/combining structure 130 through an output end 124, and under the splitting action of the splitting/combining structure 130, one path of light is split into N paths and enters a phase controller 141 forming a phase control array 140, respectively, and under the regulation and control of a heating electrode 1411, the regulation and control of a phase without a light path is realized, and the emission at a certain angle is realized through an optical antenna 150. After being reflected by an object, the reflected light enters the optical antenna 150 at the same angle, enters the 1 × N splitting/combining structure 130 through the phase control area 140, combines N paths of light into 1 path of light under the action of the combined beam, enters the isolation device 120 through the port 124 of the isolation device 120, and finally enters the photodetector 110 through the port 126, thereby completing the detection of the reflected signal. The pitch physical distance information is understood via the corresponding signal.

Claims

1. The laser radar transmitting and receiving device of the optical phased array is characterized in that: the system comprises an integrated optical chip, an optical signal isolation device, a 1 XN beam splitter/combiner, a phase control array, an optical antenna, a laser, a photoelectric detector, a signal processing module and a temperature control module; the optical signal isolation device is respectively connected with the laser, the photoelectric detector and the 1 xN beam splitter/combiner; the 1 xN beam splitter/combiner is connected with the phase control array; the 1 xN beam splitter/combiner consists of cascaded 1 xM beam splitters/combiners, wherein M is an integer greater than or equal to 2; the optical antenna is respectively connected with N ports of the 1 XN beam splitter/combiner; the integrated optical chip is composed of a core layer and a cladding layer.

2. The optical phased array lidar transmitting and receiving apparatus according to claim 1, wherein: the frequency response of the signal isolation device, the 1 XN beam splitter/combiner and the optical antenna is matched with the frequency response of the laser and the photoelectric detector.

3. The optical phased array lidar transmitting and receiving apparatus according to claim 1, wherein: the beam splitting/combining device at least comprises the following structures: array waveguide grating, directional coupler, Mach-Zehnder interferometer, micro-ring resonator, Y branch, and multi-mode interferometer.

4. The optical phased array lidar transmitting and receiving apparatus according to claim 1, wherein: the phase control array controls the phase of the optical signal by applying at least one of the following to the waveguide constituting the phase controller: heat, light, current, voltage, stress.

5. The optical phased array lidar transmitting and receiving apparatus according to claim 1, wherein: the refractive index of the integrated optical chip core layer is greater than that of the cladding layer.

6. The optical phased array lidar transmission and reception apparatus according to claim 5, wherein: the core layer material of the integrated optical chip at least comprises one of the following materials: silicon, silicon nitride, silicon oxynitride, doped silicon dioxide, indium phosphide alloy, gallium arsenide alloy, organic polymer, lithium niobate, lithium carbonate.

7. The optical phased array lidar transmission and reception apparatus according to claim 5, wherein: the cladding of the integrated optical chip can be divided into an upper cladding and a lower cladding, the materials for forming the upper cladding and the lower cladding can be different, and the integrated optical chip at least comprises one of the following materials: silicon dioxide, low refractive index silicon oxynitride, doped silicon dioxide, indium phosphide alloy, gallium arsenide alloy, organic polymer, air.