CN219200797U

CN219200797U - Testing device for optical chip waveguide mode

Info

Publication number: CN219200797U
Application number: CN202223476697.9U
Authority: CN
Inventors: 陆龙钊; 胡彦斌; 郝婷; 卢金龙; 周赤; 吉贵军; 刘昆; 黄杭东
Original assignee: ADVANCED FIBER RESOURCES (ZHUHAI) Ltd
Current assignee: ADVANCED FIBER RESOURCES (ZHUHAI) Ltd
Priority date: 2022-12-26
Filing date: 2022-12-26
Publication date: 2023-06-16
Anticipated expiration: 2032-12-26

Abstract

The utility model provides a testing device for a waveguide mode of an optical chip, which comprises a light source, a polarization maintaining optical fiber, an optical chip to be tested, an amplifying lens assembly and a plane detector, wherein the polarization maintaining optical fiber is connected with the light source, the optical fiber outgoing end of the polarization maintaining optical fiber is separated from the waveguide incoming end of the optical chip to be tested and outputs Gaussian beams to the waveguide incoming end, and outgoing light of the waveguide outgoing end of the optical chip to be tested is amplified through imaging of the amplifying lens assembly and then is incident to the plane detector. When the light incidence angle required for exciting the highest-order mode of the optical waveguide is within the far-field divergence angle of the Gaussian beam at the optical fiber emergent end, the optical fiber emergent end is transversely moved in a plane parallel to the plane where the optical waveguide incident end is located, the aim of sequentially exciting each-order mode of the waveguide can be achieved, then an imaging system is built by using the amplifying lens assembly and the plane detector, the mode of the waveguide can be judged by obtaining mode spot imaging, and then the waveguide mode of the optical chip can be simply and efficiently measured.

Description

Testing device for optical chip waveguide mode

Technical Field

The utility model relates to the field of optical chips, in particular to a testing device for a waveguide mode of an optical chip.

Background

The optical chip refers to a chip which utilizes an optical waveguide to perform information transmission or data operation by utilizing an optical wave and integrates modulation, transmission, demodulation and the like of an optical signal and an electric signal into the same integrated optical medium, wherein the mode of the optical waveguide is the basis and the core problem of the optical chip design.

The single-mode/basic-mode optical waveguide is a very important waveguide type, mainly comprises TE and TM two basic-mode modes, for the optical waveguide with gradient refractive index, the mode formed by the optical waveguide is generally difficult to control in the design stage, in actual manufacturing, the preparation of the single-mode optical waveguide is generally realized through test feedback and optimization and adjustment technology, and how to accurately test the mode of the optical waveguide becomes an important reference basis for technology optimization.

Disclosure of Invention

The utility model aims to provide a test device for simply and efficiently measuring the waveguide mode of an optical chip.

In order to achieve the purpose of the utility model, the utility model provides a testing device for the waveguide mode of an optical chip, which is characterized by comprising a light source, a polarization maintaining optical fiber, an optical chip to be tested, an amplifying lens assembly and a plane detector, wherein the polarization maintaining optical fiber is connected with the light source, and the optical fiber outgoing end of the polarization maintaining optical fiber is separated from the waveguide incident end of the optical chip to be tested and outputs Gaussian beams to the waveguide incident end; the optical chip to be tested, the amplifying lens component and the plane detector are sequentially arranged along the light path direction, and emergent light at the waveguide emergent end of the optical chip to be tested is amplified through imaging of the amplifying lens component and then is incident to the plane detector.

In a further aspect, the exit end of the optical fiber is movable parallel to the plane of the entrance end of the waveguide.

In a further scheme, the end face of the optical fiber emergent end is an optical fiber end face or an optical fiber lens which is vertically cut flat.

In a further scheme, a negative lens or a positive lens is arranged between the optical fiber emergent end and the waveguide incident end, and the Gaussian beam passes through the negative lens or the positive lens.

In a further scheme, the cat eye connecting line of the optical fiber emergent end is parallel to the extension plane of the substrate of the optical chip to be tested.

In a further scheme, the cat eye connection line of the optical fiber outgoing end is perpendicular to the extension plane of the substrate of the optical chip to be tested.

The utility model has the beneficial effects that when the light incidence angle required for exciting the highest-order mode of the optical waveguide is within the far-field divergence angle of the Gaussian beam at the optical fiber emergent end, and the optical fiber emergent end is moved up and down or left and right in parallel to the plane of the optical waveguide incident end, the aim of sequentially exciting each-order mode of the waveguide can be fulfilled, then an imaging system is built by using an amplifying lens component and a plane detector, an image of an amplified waveguide emergent mode field can be obtained by using an image distance larger than an object distance, the mode of the waveguide can be judged according to the characteristics of the image, and then the waveguide mode of the optical chip can be simply and efficiently measured. In addition, when the cat eye connection lines of the polarization maintaining optical fibers are respectively parallel and perpendicular to the optical chip, the cat eye connection lines correspond to TE mode and TM mode of the test optical waveguide. In addition, if the far-field divergence angle of the optical fiber is smaller than the light incidence angle required by the highest order of the optical waveguide, a negative lens or a positive lens can be additionally arranged, or a vertical and flat optical fiber end face or an optical fiber lens can be directly prepared on the end face of the optical fiber emergent end, so that the divergence angle is increased, and the test effect is better improved.

Drawings

FIG. 1 is a block diagram of an embodiment of a testing apparatus for optical chip waveguide modes according to the present utility model.

FIG. 2 is a schematic diagram of the optical path of an embodiment of the optical chip waveguide mode test device of the present utility model.

The utility model is further described below with reference to the drawings and examples.

Detailed Description

Referring to fig. 1 to 2, the testing device of the present disclosure is used in a waveguide mode of an optical chip, and includes a light source (not shown), a polarization maintaining fiber 14, an optical chip 13 to be tested, a magnifying lens assembly 12, and a plane detector 11, where the light source may be a semiconductor laser, a solid laser, or other commonly used lasers capable of generating laser, the polarization maintaining fiber 14 is connected to the light source, an optical fiber exit end 141 of the polarization maintaining fiber 14 is separated from a waveguide entrance end 131 of the optical chip 13 to be tested and maintains a distance, the optical fiber exit end 141 of the polarization maintaining fiber 14 outputs a gaussian beam 142 to the waveguide entrance end 131, and when a light incident angle required for exciting a highest order mode of the optical waveguide is within a far field angle of the gaussian beam 142, and moves transversely parallel to the plane of the waveguide entrance end 131 through the optical fiber exit end 141, thereby achieving the purpose of sequentially exciting each order mode of the waveguide.

In a specific measurement, the polarization maintaining optical fiber 14 includes a cladding 144 and a fiber core 143, two stress rods are disposed in the fiber core 143 and form a cat eye, the polarization maintaining optical fiber 14 is connected to a light source and outputs linearly polarized light, the polarization direction is generally selected to be along a slow axis (polarization maintaining optical fiber cat eye) for incident light, when a cat eye connection line L2 of the optical fiber outgoing end 141 is parallel to an extension plane of a substrate of the optical chip 13 to be measured, a TE mode of the test optical waveguide is corresponding, and when a cat eye connection line L1 of the optical fiber outgoing end 141 is perpendicular to the extension plane of the substrate of the optical chip 13 to be measured, a TM mode of the test optical waveguide is corresponding. Cat eye wiring is not present in real products, and it is used as this case auxiliary mark orientation. Of course, it is also possible to choose to inject light along the fast axis, which can also achieve the present object.

The optical chip 13 to be tested, the amplifying lens assembly 12 and the plane detector 11 are sequentially arranged along the direction of the optical path, the incident light is transmitted by the optical waveguide 133 of the optical chip 13 to be tested and excites each order mode, the emergent light of the waveguide emergent end 132 of the optical chip 13 to be tested is amplified by the imaging of the amplifying lens assembly 12 and then is incident to the plane detector 11, the image distance is made to be larger than the object distance, the mode spot 111 of the amplified waveguide emergent mode field can be obtained, and then the mode of the waveguide can be judged according to the characteristics of the mode spot 111.

In addition, the far-field divergence angle of the optical fiber exit end 141 of the optical fiber is smaller than the light incident angle required by the highest order of the optical waveguide, a negative lens can be arranged between the optical fiber exit end 141 and the waveguide incident end 131, and the gaussian beam 142 diverges and transmits through the negative lens, so that the divergence angle is increased, and the test effect is better improved. And a positive lens may be disposed between the optical fiber exit end 141 and the waveguide entrance end 131, and the divergence angle may be increased by converging the positive lens and then diverging the positive lens, and furthermore, a vertical and flat optical fiber end surface or an optical fiber lens may be directly prepared at the optical fiber exit end 141, and the optical fiber lens may be divided into an inclined plane, a wedge shape, a spherical surface, a conical shape, and the like, so long as the optical fiber lens is incident to the optical chip 13 to be measured in a divergent state, the purpose of the present utility model may be achieved.

From the above, when the light incidence angle required for exciting the highest-order mode of the optical waveguide is within the far-field divergence angle of the gaussian beam at the optical fiber emergent end, and the optical fiber emergent end is moved transversely in parallel to the plane where the waveguide incident end is located, then the purpose of sequentially exciting each-order mode of the waveguide can be achieved, then an imaging system is built by using an amplifying lens assembly and a plane detector, an image of an amplified waveguide emergent mode field can be obtained through an image distance being larger than an object distance, the mode of the waveguide can be judged according to the characteristics of the image, and then the waveguide mode of the optical chip can be simply and efficiently measured.

Claims

1. The testing device for the waveguide mode of the optical chip is characterized by comprising a light source, a polarization maintaining optical fiber, an optical chip to be tested, an amplifying lens assembly and a plane detector, wherein the polarization maintaining optical fiber is connected with the light source, and an optical fiber outgoing end of the polarization maintaining optical fiber is separated from a waveguide incident end of the optical chip to be tested and outputs Gaussian beams to the waveguide incident end;

the optical chip to be tested, the amplifying lens component and the plane detector are sequentially arranged along the direction of the optical path, and emergent light at the waveguide emergent end of the optical chip to be tested is amplified by the imaging of the amplifying lens component and then enters the plane detector.

2. The optical chip waveguide mode testing device according to claim 1, wherein:

the optical fiber exit end can move parallel to the plane where the waveguide incident end is located.

3. The optical chip waveguide mode testing device according to claim 1, wherein:

the optical fiber emergent end is an optical fiber end face or an optical fiber lens which is vertically cut and flattened.

4. The optical chip waveguide mode testing device according to claim 1, wherein:

a negative lens or a positive lens is arranged between the optical fiber emergent end and the waveguide incident end, and the Gaussian beam passes through the negative lens or the positive lens.

5. The optical chip waveguide mode testing apparatus according to any one of claims 1 to 4, wherein:

and the cat eye connecting line of the optical fiber outgoing end is parallel to the extension plane of the substrate of the optical chip to be tested.

6. The optical chip waveguide mode testing apparatus according to any one of claims 1 to 4, wherein:

and the cat eye connecting line of the optical fiber outgoing end is perpendicular to the extension plane of the substrate of the optical chip to be tested.