CN112886392A

CN112886392A - Multi-segment light amplifying coupler with optical switching function

Info

Publication number: CN112886392A
Application number: CN202110039320.8A
Authority: CN
Inventors: 祝宁华; 徐长达; 刘泽秋; 袁海庆
Original assignee: Institute of Semiconductors of CAS
Current assignee: Institute of Semiconductors of CAS
Priority date: 2021-01-12
Filing date: 2021-01-12
Publication date: 2021-06-01
Anticipated expiration: 2041-01-12
Also published as: CN112886392B

Abstract

The present disclosure provides a multi-section optical amplifying coupler with optical switching, comprising: a substrate layer; a lower confinement layer disposed on the substrate layer; the lower waveguide layer is arranged on the lower limiting layer; an active layer disposed on the lower waveguide layer for generating optical gain; an upper waveguide layer disposed on the active layer; the upper limiting layer is arranged on the upper waveguide layer, and a ridge waveguide group is prepared on the upper limiting layer; the insulating layer is arranged on the upper limiting layer and the side wall of the ridge waveguide group; and an ohmic contact layer disposed on the ridge waveguide group; and multiple sections of separated P-surface electrodes are arranged on the surfaces of the insulating layer and the ohmic contact layer, and after the set current is injected, the optical amplification coupler with an input amplifier section, a coupling amplifier section and an output amplifier section is formed.

Description

Multi-segment light amplifying coupler with optical switching function

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to a multi-section optical amplifying coupler with an optical switching function.

Background

In recent years, with the explosion development of the optical communication industry, the optical fiber communication technology develops from the initial single-wavelength optical time division multiplexing to the multi-wavelength optical wavelength division multiplexing which is widely used at present, and the next development goal is to establish an all-optical network, and an optical switch and an optical amplifier are important devices of the all-optical network. The optical switch plays a role of optical interconnection between the upper and lower path signals and other optical paths and controls the on-off of the optical paths; the optical amplifier is mainly used for amplifying input light, compensating the loss of the light in a link and providing energy supply for an optical network.

The optical amplifier mainly comprises an erbium-doped fiber amplifier (EDFA) and a Semiconductor Optical Amplifier (SOA), the EDFA has obvious advantages for signal amplification of a 1.5um waveband, but has no amplification capability for light of a 1.3um waveband, the gain wavelength of the SOA can be controlled by adjusting active layer components, the SOA also has larger gain bandwidth, and optical amplification outside the 1.5um waveband can be realized. Therefore, with the continuous advance of all-optical networks, the whole communication system will have higher demand for SOA devices in the future.

At present, integrated optical switches at home and abroad mainly have the following types, including micro mechanical systems (MEMS), Mach-Zehnder interferometers (MZI), multi-mode interference coupling (MMI), micro-ring structures and directional coupling structures. The MEMS optical switch has a slow response speed, and the micro-ring structure has high requirements on precision. MZI and MMI structure, the power consumption is great. The optical switches are all based on silica-based materials, the silica-based waveguide and the optical fiber have large optical coupling loss, and the silica-based materials are difficult to play a role in amplification compensation for communication wavelengths.

With the development of optoelectronic integrated devices, the need for optical switches to be present in an integrated circuit simultaneously with optical amplifiers is increasing. However, the conventional method for integrating the devices on the discrete chips through the bonding process has the defects of large coupling loss between the devices on the chips, high system complexity, large energy consumption, large volume, low reliability and the like.

Disclosure of Invention

Technical problem to be solved

Based on the above problems, the present disclosure provides a multi-segment optical amplifying coupler with optical switching function, so as to alleviate the technical problems of large coupling loss, high system complexity, large energy consumption, large volume, low reliability, etc. of the prior art when discrete devices on a chip are integrated together through a bonding process.

(II) technical scheme

In an embodiment of the present disclosure, the set of ridge waveguides includes an input ridge waveguide, and an output ridge waveguide.

In the disclosed embodiment, the input ridge waveguide and the output ridge waveguide in the input amplifier section and the output amplifier section are not optically coupled with each other, and are non-coupling regions.

In the embodiment of the present disclosure, the manner of forming the non-coupling region includes: expanding the spacing between the input ridge waveguide and the output ridge waveguide; or an isolation layer or an absorption region is filled between the input ridge waveguide and the output ridge waveguide.

In the disclosed embodiments, the input ridge waveguide and the output ridge waveguide of the coupled amplifier segment are coupled by a reduced pitch.

In the disclosed embodiment, the coupled amplifier segments are coupled by disposing a straight waveguide between the input ridge waveguide and the output ridge waveguide.

In embodiments of the present disclosure, the coupled amplifier segments are coupled by placing a micro-ring waveguide between an input ridge waveguide and an output ridge waveguide.

In an embodiment of the disclosure, the coupled amplifier segments are coupled by a multimode interference structure.

In the disclosed embodiment, the input ridge waveguide or the output ridge waveguide is in a form selected from a straight waveguide, an inclined waveguide, or a curved waveguide; the width of the input ridge waveguide or the output ridge waveguide adopts a gradual change type or a constant value.

In the embodiment of the disclosure, during operation, light is input from one side of the input ridge waveguide, is amplified through the input amplifier section, is coupled into the output ridge waveguide through the coupling amplifier section, and is amplified and output from the other side of the output amplifier section; the output light intensity is adjusted by controlling the electrode input current of the coupling amplifier section to enable the coupling amplifier section to be in an absorption or amplification state, and the purpose of controlling the large output light intensity across the waveguide by the small current of the coupling area is achieved.

(III) advantageous effects

From the technical scheme, the multi-section light amplification coupler with the optical switching function has at least one or part of the following beneficial effects:

(1) by utilizing the mature ridge waveguide manufacturing process, a plurality of sections of optical amplifiers are integrated on the same epitaxial wafer, and multiple times of epitaxy and butt joint growth of active layers are not needed;

(2) the manufacturing process is mature, and the purpose of controlling the large output light intensity of the cross waveguide by the small current of the coupling area can be realized.

Drawings

Fig. 1 is a schematic perspective view of a multi-segment optical amplifying coupler with optical switching according to an embodiment of the present disclosure.

Fig. 2 is a schematic top view of a multi-segment light amplifying coupler with optical switching according to an embodiment of the present disclosure.

Fig. 3 is a schematic side view of a multi-section optical amplifying coupler with optical switching according to an embodiment of the present disclosure.

Fig. 4 is a schematic structural diagram of a curved ridge waveguide assembly of a multi-segment light amplifying coupler with optical switching according to an embodiment of the present disclosure.

Fig. 5 is a schematic structural diagram of a multi-segment light amplifying coupler with optical switching function, in which one light-emitting surface is a side surface and a curved ridge waveguide group is adopted.

Fig. 6 is a schematic structural diagram of a ridge waveguide group having an antireflection structure on one end face of a multi-segment light amplifying coupler with an optical switching function according to an embodiment of the present disclosure.

Fig. 7 is a schematic structural diagram of a coupling amplifier segment input ridge waveguide and an output ridge waveguide of a multi-segment optical amplifying coupler with an optical switching function according to an embodiment of the present disclosure, in which a straight waveguide is disposed between the input ridge waveguide and the output ridge waveguide for coupling.

Fig. 8 is a schematic structural diagram of a coupling amplifier segment of a multi-segment optical amplifying coupler with optical switching function coupled by a micro-ring waveguide structure.

Fig. 9 is a schematic structural diagram of a coupling amplifier segment of a multi-segment optical amplifying coupler with optical switching function according to an embodiment of the present disclosure, which is coupled by a micro-ring waveguide structure and has a light-emitting surface as a side surface.

[ description of main reference numerals in the drawings ] of the embodiments of the present disclosure

1-a substrate layer; 2-a lower limiting layer; 3-a lower waveguide layer; 4-an active layer;

5-an upper waveguide layer; 6-upper limiting layer; 7-an insulating layer; 8-ridge waveguide set;

9-P-plane electrode; 10-an input ridge waveguide; 11 output ridge waveguides.

Detailed Description

The present disclosure provides a multi-segment optical amplifying coupler with optical switching, which includes an input ridge waveguide and an output ridge waveguide, each of which can be regarded as a multi-segment optical amplifier, and a plurality of electrodes are provided to perform different control on each segment. By designing the waveguide shape such that input light can be coupled from the input ridge waveguide to the output ridge waveguide only at the coupling region. Therefore, light is input from one side of the input ridge waveguide, is amplified by the optical amplifier, enters the output ridge waveguide through the coupling region, is amplified from the other side of the output ridge waveguide and is output; light that remains in the input ridge waveguide after passing through the coupling region is also absorbed by the optical amplifier without current injection, which, together with the anti-reflection structure, prevents the light from oscillating back and forth in the waveguide. In addition, the present disclosure can control the current of the coupling region to make the optical amplifier in the coupling region in an amplification or absorption state, and thus control the final output light intensity of the output ridge waveguide. Because the transparent current of the optical amplifier is much smaller than the working current, the multi-section optical amplification coupler can achieve the purpose that the small current of the coupling area controls the large output light intensity of the cross waveguide. The present disclosure has the same epitaxial layer structure, does not require multiple epitaxy and butt growth, and can be fabricated using a mature ridge waveguide process.

For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

In an embodiment of the present disclosure, there is provided a multi-segment optical amplifying coupler with optical switching function, as shown in fig. 1 to 9, including:

a substrate layer 1;

a lower limiting layer 2 disposed on the substrate layer;

the lower waveguide layer 3 is arranged on the lower limiting layer;

an active layer 4 disposed on the lower waveguide layer for generating optical gain;

an upper waveguide layer 5 disposed on the active layer;

an upper confinement layer 6 disposed on the upper waveguide layer, the upper confinement layer being prepared with a group of ridge waveguides;

an insulating layer 7 disposed on the upper confinement layer and on the sidewalls of the ridge waveguide group;

the ohmic contact layer is arranged on the ridge waveguide group 8;

the surfaces of the insulating layer and the ohmic contact layer are provided with a plurality of sections of separated P-surface electrodes 9, and after the set current is injected respectively, an optical amplification coupler with an input amplifier section, a coupling amplifier section and an output amplifier section is formed.

In the disclosed embodiment, the ridge waveguide set includes an input ridge waveguide 10, and an output ridge waveguide 11;

in the disclosed embodiment, the input ridge waveguide and the output ridge waveguide in the input amplifier section and the output amplifier section cannot be mutually optically coupled; the non-coupling region is formed mainly by enlarging the space between the input ridge waveguide and the output ridge waveguide, and filling the isolation layer and the absorption region between the input ridge waveguide and the output ridge waveguide.

In the disclosed embodiment, only the coupling amplifier section couples the light input from the input ridge waveguide to the output ridge waveguide and then outputs the light, and the coupling amplifier section is located in the middle section of the optical amplification coupler; the input amplifier section and the output amplifier section are located at the edge of the optical amplifying coupler, for example, as shown in fig. 1 to 3, and the input amplifier section and the output amplifier section are located at the left and right ends of the optical amplifying coupler, respectively.

In the disclosed embodiment, as shown in fig. 4-6, the input ridge waveguide and the output ridge waveguide of the coupled amplifier segment are coupled by a reduced pitch; or as shown in fig. 7, the coupling amplifier section is coupled by arranging a straight waveguide between the input ridge waveguide and the output ridge waveguide; or as shown in fig. 8-9, the coupled amplifier segments are coupled by placing a micro-ring waveguide between the input ridge waveguide and the output ridge waveguide; or by MMI (Multimode Interference) structures.

In the embodiment of the present disclosure, as shown in fig. 2, a plurality of independent P-plane electrodes 9 are disposed on the insulating layer 7 beside the ridge waveguide group and the ohmic contact layer on the surface of the ridge waveguide group. The multi-section light amplification coupler forms two ridge waveguide structures, namely an input ridge waveguide and an output ridge waveguide, through etching, and is characterized in that the input ridge waveguide and the output ridge waveguide only form an optical coupling region in the middle section part, and the rest ridge waveguide parts cannot be mutually optically coupled. The P-surface electrode carries out different current injection on different sections (an input amplifier section, a coupling amplifier section and an output amplifier section) to form a multi-section light amplification coupler.

In the embodiment of the present disclosure, as shown in fig. 1 and fig. 3, when the ridge waveguide group is etched, a shallow etching structure is etched to the upper limiting layer, but the multi-segment optical amplification coupler is not limited to adopt a shallow etching scheme, and may also adopt a deep etching scheme that is etched to the upper waveguide layer, the active layer, or even the lower waveguide layer and the lower limiting layer.

In the disclosed embodiment, the ridge waveguides in the ridge waveguide group can adopt various groups and forms of straight waveguides, inclined waveguides and bent waveguides; the width of the ridge waveguide in the ridge waveguide group can adopt various groups and modes of gradual change and constant value; the lengths of the front and back sections of the ridge waveguides in the ridge waveguide group can take different values.

In the embodiment of the present disclosure, it is possible to ensure that two ridge waveguides do not optically couple in the non-coupling region by controlling the pitch of the ridge waveguides, but the multi-section light amplification coupler is not limited to this, and may also adopt various manners such as providing an optical isolation region and an absorption region.

In the embodiment of the present disclosure, as shown in fig. 2, the front and rear sections of the input ridge waveguide and the output ridge waveguide are controlled by four mutually independent electrodes, but the middle sections of the two ridge waveguides, i.e., the coupling amplifier section, may be controlled by one or more electrodes according to different coupling modes.

When the input ridge waveguide is in operation, light is input from one side of the input ridge waveguide, amplified through the input amplifier section, coupled through the coupling amplifier section, enters the output ridge waveguide, amplified from the other side of the output amplifier section, and then output. The light still remained in the input ridge waveguide after passing through the coupling amplification section can be absorbed by the output optical amplifier without current injection, and the light is prevented from oscillating back and forth in the input ridge waveguide under the coaction with the anti-reflection structure. Therefore, in application, the output light intensity is adjusted by controlling the coupling amplifier section to be in an absorption or amplification state, and the purpose of controlling the large output light intensity across the waveguide by the small current in the coupling region can be realized.

So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It is to be noted that, in the attached drawings or in the description, the implementation modes not shown or described are all the modes known by the ordinary skilled person in the field of technology, and are not described in detail. Further, the above definitions of the various elements and methods are not limited to the various specific structures, shapes or arrangements of parts mentioned in the examples, which may be easily modified or substituted by those of ordinary skill in the art.

From the above description, those skilled in the art should clearly recognize that the multi-section light amplifying coupler of the present disclosure has the optical switching function.

In summary, the present disclosure provides a multi-segment optical amplifying coupler with optical switching function, which controls the current of the coupled amplifier segment (coupling region) to make the coupled amplifier segment in the amplifying or absorbing state, and thus controls the final output light intensity of the output ridge waveguide. Because the transparent current of the optical amplifier is much smaller than the working current, the multi-section optical amplification coupler can achieve the purpose that the small current of the coupling area controls the large output light intensity of the cross waveguide. The present disclosure has the same epitaxial layer structure, does not require multiple epitaxy and butt growth, and can be fabricated using a mature ridge waveguide process.

It should also be noted that directional terms, such as "upper", "lower", "front", "rear", "left", "right", and the like, used in the embodiments are only directions referring to the drawings, and are not intended to limit the scope of the present disclosure. Throughout the drawings, like elements are represented by like or similar reference numerals. Conventional structures or constructions will be omitted when they may obscure the understanding of the present disclosure.

And the shapes and sizes of the respective components in the drawings do not reflect actual sizes and proportions, but merely illustrate the contents of the embodiments of the present disclosure. Furthermore, in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

The use of ordinal numbers such as "first," "second," "third," etc., in the specification and claims to modify a corresponding element does not by itself connote any ordinal number of the element or any ordering of one element from another or the order of manufacture, and the use of the ordinal numbers is only used to distinguish one element having a certain name from another element having a same name.

In addition, unless steps are specifically described or must occur in sequence, the order of the steps is not limited to that listed above and may be changed or rearranged as desired by the desired design. The embodiments described above may be mixed and matched with each other or with other embodiments based on design and reliability considerations, i.e., technical features in different embodiments may be freely combined to form further embodiments.

Those skilled in the art will appreciate that the modules in the device in an embodiment may be adaptively changed and disposed in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and furthermore they may be divided into a plurality of sub-modules or sub-units or sub-components. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Also in the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware.

The above-mentioned embodiments are intended to illustrate the objects, aspects and advantages of the present disclosure in further detail, and it should be understood that the above-mentioned embodiments are only illustrative of the present disclosure and are not intended to limit the present disclosure, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.

Claims

1. A multi-section optically amplified coupler with optical switching, comprising:

a substrate layer;

a lower confinement layer disposed on the substrate layer;

the lower waveguide layer is arranged on the lower limiting layer;

an active layer disposed on the lower waveguide layer for generating optical gain;

an upper waveguide layer disposed on the active layer;

the upper limiting layer is arranged on the upper waveguide layer, and a ridge waveguide group is prepared on the upper limiting layer;

the insulating layer is arranged on the upper limiting layer and the side wall of the ridge waveguide group; and

the ohmic contact layer is arranged on the ridge waveguide group;

and multiple sections of separated P-surface electrodes are arranged on the surfaces of the insulating layer and the ohmic contact layer, and after the set current is injected, the optical amplification coupler with an input amplifier section, a coupling amplifier section and an output amplifier section is formed.

2. The optically switchable multi-segment light amplifying coupler of claim 1, the set of ridge waveguides including an input ridge waveguide and an output ridge waveguide.

3. The multi-section optical amplifying coupler with optical switching according to claim 2, wherein the input ridge waveguide and the output ridge waveguide in the input amplifier section and the output amplifier section are not optically coupled with each other and are non-coupling regions.

4. The multi-section optically amplified coupler of claim 3, having optical switching, the non-coupling region being formed by: expanding the spacing between the input ridge waveguide and the output ridge waveguide; or an isolation layer or an absorption region is filled between the input ridge waveguide and the output ridge waveguide.

5. The optically switched, multi-section optically amplified coupler of claim 2, wherein the input and output ridge waveguides of the coupled amplifier section are coupled by a reduced pitch.

6. The optically switchable multi-section optically amplifying coupler of claim 2, wherein the coupled amplifier sections are coupled by providing a straight waveguide between the input ridge waveguide and the output ridge waveguide.

7. The optically-switched, multi-section optically-amplified coupler of claim 2, wherein the coupled amplifier sections are coupled by placing a micro-ring waveguide between the input ridge waveguide and the output ridge waveguide.

8. The optically switchable multi-section optically amplifying coupler of claim 2, the coupled amplifier sections being coupled by a multi-mode interference structure.

9. The multistage light amplifying coupler with optical switching according to claim 2, wherein the input ridge waveguide or the output ridge waveguide is in a form selected from a straight waveguide, an inclined waveguide, or a curved waveguide; the width of the input ridge waveguide or the output ridge waveguide adopts a gradual change type or a constant value.

10. The multi-section optical amplifying coupler with optical switching according to claim 2, wherein in operation, light is input from one side of the input ridge waveguide, amplified by the input amplifier section, coupled into the output ridge waveguide by the coupling amplifier section, and amplified and output from the other side of the output amplifier section; the output light intensity is adjusted by controlling the electrode input current of the coupling amplifier section to enable the coupling amplifier section to be in an absorption or amplification state, and the purpose of controlling the large output light intensity across the waveguide by the small current of the coupling area is achieved.