Light-emitting assembly and optical module

Abstract

Disclosed in the present utility model are a light-emitting assembly and an optical module. The light-emitting assembly comprises a light output unit and an optical chip, wherein the light output unit is used for outputting vertical polarized light; the optical chip is sequentially connected to a first coupling unit, an optical processing unit and a second coupling unit in an optical signal propagation direction by means of an optical transmission waveguide; the first coupling unit is used for receiving the vertical polarized light, coupling the vertical polarized light and then outputting the coupled vertical polarized light; the optical processing unit is used for receiving the coupled vertical polarized light, processing the coupled vertical polarized light and outputting the processed vertical polarized light; the second coupling unit is used for receiving the processed vertical polarized light, coupling the processed vertical polarized light and then outputting the coupled vertical polarized light outside the optical chip; and the thickness of at least part of the optical transmission waveguide is greater than or equal to 250 nm, so that the transmission loss of the vertical polarized light in the optical chip can be reduced.

Description

Optical transmitter components and optical modules

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 28, 2023, with application number 202323621271.2 and invention name “Optical Transmitter Assembly and Optical Module”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The utility model relates to the technical field of semiconductor integration, in particular to a light emitting component and a light module. Background Art

[0003] Currently, silicon photonics chips primarily utilize the TE mode. The width of the optical waveguide is typically about twice its thickness, resulting in a laterally flattened optical field distribution in the TE mode. This is primarily due to the fact that the top silicon thickness of most silicon photonics foundries' silicon photonics platforms is 220nm or less. This thickness of silicon poorly confines the TM mode optical field, negatively impacting the performance of both active and passive components.

[0004] However, the TE mode also has certain disadvantages. For example, in the modulator, the overlap between the light field and the PN junction depletion layer is low, resulting in low modulation efficiency. In addition to being detrimental to the modulator, the TE mode is also detrimental to the loss of passive components. The electric field in the TE mode vibrates horizontally, interacting more strongly with the left and right sidewalls of the waveguide. However, the left and right sidewalls of the waveguide are etched and have poor roughness, resulting in large waveguide losses. In contrast, the electric field in the TM mode vibrates vertically, interacting more strongly with the upper and lower edges of the waveguide. However, the upper and lower edges of the waveguide are polished and have good roughness, resulting in lower waveguide losses. Utility Model Content

[0005] The purpose of the utility model is to provide an optical transmission component and an optical module to reduce the transmission loss of light in an optical chip.

[0006] To achieve one of the above-mentioned purposes of the utility model, an embodiment of the utility model provides a light emitting assembly, the light emitting assembly comprising a light output unit and an optical chip;

[0007] The light output unit is used to output vertically polarized light;

[0008] The optical chip is connected in sequence along the propagation direction of the optical signal through an optical transmission waveguide: a first coupling unit, an optical processing unit, and a second coupling unit;

[0009] The first coupling unit is used to receive the vertically polarized light, and output the vertically polarized light after coupling;

[0010] The light processing unit is used to receive the coupled vertical polarized light, process the coupled vertical polarized light, and output the processed vertical polarized light;

[0011] The second coupling unit is used to receive the processed vertically polarized light, couple the processed vertically polarized light, and output it to the outside of the optical chip;

[0012] The thickness of at least a portion of the light transmission waveguide is greater than or equal to 250 nm.

[0013] As a further improvement of one embodiment of the present invention, the optical chip also includes a beam splitting unit, which is connected to the output end of the first coupling unit and is used to split the coupled vertically polarized light into at least two transmission paths, and each transmission path is connected to the optical processing unit and the second coupling unit.

[0014] As a further improvement of one embodiment of the present invention, the optical chip also includes a mode filtering unit, which is connected to the first coupling unit and the optical processing unit, and its input end is connected to the output end of the first coupling unit, for allowing only vertically polarized light to pass through.

[0015] As a further improvement of an embodiment of the present invention, the optical processing unit includes an optical modulator, the optical modulator includes a modulation electrode and a modulation waveguide, and the modulation waveguide is connected to the optical transmission waveguide;

[0016] The thickness of the modulation waveguide is set to be greater than or equal to 250 nm.

[0017] As a further improvement of an embodiment of the present invention, the light transmission waveguide is a silicon nitride waveguide and / or a silicon waveguide.

[0018] As a further improvement of an embodiment of the present invention, when the optical transmission waveguide is a silicon nitride waveguide, the thickness of the optical transmission waveguide is set to be greater than or equal to 250 nm; when the optical transmission waveguide is a silicon waveguide, the thickness of the optical transmission waveguide is set to be greater than or equal to 265 nm.

[0019] As a further improvement of one embodiment of the present invention, when the optical transmission waveguide is a silicon nitride waveguide and a silicon waveguide, a waveguide conversion structure is provided at the connection between the silicon nitride waveguide and the silicon waveguide, and the waveguide conversion structure is used for optical coupling between the silicon nitride waveguide and the silicon waveguide.

[0020] As a further improvement of one embodiment of the present invention, the light output unit includes a laser emitting unit and a spatial coupling unit, the laser emitting unit is used to output horizontally polarized light, and the spatial coupling unit is arranged between the laser emitting unit and the optical chip, and is used to receive the horizontally polarized light, change the polarization state of the horizontally polarized light, and output the vertically polarized light.

[0021] As a further improvement of one embodiment of the present invention, the spatial coupling unit includes a lens, an isolator and a wave plate, the lens is arranged close to the laser emitting unit, and the wave plate is arranged close to the optical chip, for converting the horizontally polarized light into vertically polarized light output; the isolator is arranged between the lens and the wave plate.

[0022] In order to achieve one of the above-mentioned purposes of the utility model, the utility model further provides an optical module, which has the above-mentioned light emitting component.

[0023] The beneficial effect of this utility model is that the optical chip in the optical transmitter assembly receives vertically polarized light at the end optically coupled to the output light of the optical output unit. Compared to conventional solutions in which the optical chip transmits horizontally polarized light from reception to output, the optical chip's internal spot conversion unit, optical processing unit, and waveguide for transmitting optical signals transmit vertically polarized light at higher input optical power levels, significantly reducing nonlinear losses caused by optical transmission within the optical chip. Furthermore, by increasing the thickness of the optical transmission waveguide, the transmission loss of vertically polarized light can be further reduced, thereby improving the overall performance of the optical chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic diagram of a light emitting assembly in one embodiment of the present invention;

[0025] FIG2 is a schematic diagram of a light emitting assembly in another embodiment of the present invention. DETAILED DESCRIPTION

[0026] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the specific embodiments of this application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0027] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0028] The utility model provides a light emitting component, which includes a light output unit and an optical chip;

[0029] The light output unit is used to output vertically polarized light;

[0030] The optical chip is connected in sequence along the propagation direction of the optical signal through an optical transmission waveguide: a first coupling unit, an optical processing unit, and a second coupling unit;

[0031] The first coupling unit is used to receive the vertically polarized light, and output the vertically polarized light after coupling;

[0032] The light processing unit is used to receive the coupled vertical polarized light, process the coupled vertical polarized light, and output the processed vertical polarized light;

[0033] The second coupling unit is used to receive the processed vertically polarized light, couple the processed vertically polarized light, and output it to the outside of the optical chip;

[0034] The thickness of at least a portion of the light transmission waveguide is greater than or equal to 250 nm.

[0035] As shown in FIG1 , an embodiment of the present invention provides a light emitting assembly, including a light output unit 1 and an optical chip 2 .

[0036] The light output unit 1 is used to output vertically polarized light.

[0037] The optical chip 2 is optically coupled to the optical output unit 1 to receive the vertically polarized light output by the optical output unit 1. Specifically, the optical chip 2 is sequentially connected to the first coupling unit 21, the optical processing unit 22, and the second coupling unit 23 via an optical transmission waveguide along the propagation direction of the optical signal.

[0038] The first coupling unit 21 is used to receive the vertically polarized light output by the optical output unit 1 and couple the vertically polarized light for output. Because the electric field vibration direction of vertically polarized light is vertical, it interacts more strongly with the upper and lower edges of the optical transmission waveguide. The upper and lower edges of the optical transmission waveguide are generally polished and have a good roughness. Therefore, compared with horizontally polarized light, vertically polarized light has lower transmission loss when transmitted in the optical chip.

[0039] Specifically, the first coupling unit 21 is an edge coupler, such as a spot converter, which can be an inverted wedge-shaped spot converter, a subwavelength grating-type spot converter, or a spot converter having another structure. When the first coupling unit 21 is a spot converter, when the optical output unit 1 is optically coupled to the first coupling unit 21, the first coupling unit 21 receives external input light and reduces the spot size of the input light, so that the coupled light with the reduced spot size can be transmitted between the optical transmission waveguide on the optical chip 2 and other optical units or optical devices.

[0040] The light processing unit 22 is used to receive the coupled vertically polarized light, process the coupled vertically polarized light, and output the processed vertically polarized light.

[0041] Specifically, the light processing unit 22 at least includes a light modulator, which modulates the coupled vertically polarized light and then outputs the modulated light.

[0042] Of course, the optical processing unit 22 can also include functional devices such as wavelength division multiplexers and beam splitters. The present invention does not limit the type, quantity and setting position of the functional devices, and can be designed and adjusted according to the actual design requirements and application scenarios of the optical chip.

[0043] The second coupling unit 23 is used to receive the vertically polarized light processed by the optical processing unit 22 , couple the processed vertically polarized light, and then output it to the outside of the optical chip 2 .

[0044] Specifically, the second coupling unit 23 is an edge coupler, such as a spot converter, which can be an inverted wedge-shaped spot converter, a subwavelength grating-type spot converter, or a spot converter having another structure. When the second coupling unit 23 is a spot converter, it receives the processed vertically polarized light, performs spot amplification on the processed vertically polarized light, and outputs it to the outside of the optical chip 2.

[0045] Furthermore, the optical chip 2 in this embodiment also includes a beam splitting unit 24, which is connected to the output end of the first coupling unit 21 and is used to split the coupled vertically polarized light into at least two transmission paths, and each transmission path is connected to an optical processing unit 22 and a second coupling unit 23.

[0046] Specifically, the beam splitting unit 24 is a 3dB coupler, which splits the coupled vertical polarized light into two transmission paths, and each transmission path is connected to the optical processing unit 22 and the second coupling unit 23 .

[0047] Of course, the beam splitting unit 24 can also be designed as a multi-channel beam splitter structure, and it is only necessary to ensure that the optical power of each transmission channel meets the transmission requirements of subsequent silicon-based optical devices.

[0048] Furthermore, as shown in FIG2 , the optical chip 2 further includes a first optical power monitoring unit 25 and a second optical power monitoring unit 26 .

[0049] The first optical power monitoring unit 25 is connected to the output end of the first coupling unit 21 and is used to monitor the optical power of the coupled vertically polarized light output by the first coupling unit 21 .

[0050] The second optical power monitoring unit 26 is connected to the output end of the optical processing unit 22 and is used to monitor the optical power of the processed vertically polarized light output by the optical processing unit 22 .

[0051] Specifically, the first optical power monitoring unit 25 and the second optical power monitoring unit 26 are both optical detection devices.

[0052] Since it is difficult to ensure that the light coupled into the optical chip 2 by the first coupling unit 21 is all vertically polarized light in practical applications, the optical chip 2 in this embodiment further includes a mode filtering unit 27, which is connected to the first coupling unit 21 and the optical processing unit 22, and its input end is connected to the output end of the first coupling unit 21, and is used to allow only numerically polarized light to pass through.

[0053] Specifically, the input end of the mode filtering unit 27 is connected to the output end of the first coupling unit 21 , and the output end of the mode filtering unit 27 is connected to the input end of the beam splitting unit 24 .

[0054] More specifically, the mode filtering unit 27 is a polarization splitter or a polarization rotation splitter, and one end of the polarization splitter or the polarization rotation splitter outputting vertically polarized light is connected to the input end of the beam splitting unit 24 .

[0055] Of course, a combiner may be designed after the output end of the optical processing unit 22 to combine the two optical transmission paths into one output, and the specific design may be based on actual needs.

[0056] In this embodiment, the thickness of at least a portion of the optical transmission waveguide within the optical chip 2, used to connect various components, is greater than or equal to 250 nm. Because the electric field vibration direction of vertically polarized light propagating within the optical transmission waveguide is vertical, the interaction with the upper and lower edges of the optical transmission waveguide is stronger. Therefore, the thicker the optical transmission waveguide, the lower the transmission loss of vertically polarized light.

[0057] Of course, when the optical processing unit 22 includes an optical modulator, the optical modulator includes a modulation electrode and a modulation waveguide, the modulation waveguide is connected to the optical transmission waveguide, and the thickness of the modulation waveguide is set to be greater than or equal to 250 nm.

[0058] Specifically, the light transmission waveguide is a silicon nitride waveguide and / or a silicon waveguide.

[0059] When the light transmission waveguide is a silicon nitride waveguide, the thickness of the light transmission waveguide is set to be greater than or equal to 250 nm.

[0060] When the light transmission waveguide is a silicon waveguide, the thickness of the light transmission waveguide is set to be greater than or equal to 265 nm.

[0061] Of course, the present invention does not impose any restrictions on the specific value of the thickness of the optical transmission waveguide, and it can be adjusted according to the manufacturing process of the optical chip and actual design requirements.

[0062] Specifically, when the optical transmission waveguides are silicon nitride waveguides and silicon waveguides, a waveguide conversion structure is provided at the connection between the silicon nitride waveguide and the silicon waveguide. This waveguide conversion structure is used to couple light between the silicon nitride waveguide and the silicon waveguide. In other words, if a section of the optical transmission waveguide along the optical transmission path is composed of interconnected silicon nitride waveguides and silicon waveguides, the waveguide conversion structure can couple light transmitted by the silicon nitride waveguide into the silicon waveguide.

[0063] In this embodiment, the light output unit 1 includes a laser emitting unit 11 and a spatial coupling unit 12 .

[0064] The laser emitting unit 11 is used to output horizontally polarized light.

[0065] The spatial coupling unit 12 is disposed between the laser emitting unit 11 and the optical chip 2 , and is configured to receive horizontally polarized light, change the polarization state of the horizontally polarized light, and output vertically polarized light.

[0066] Specifically, the laser emitting unit 11 outputs horizontally polarized light with high power. In this embodiment, the laser emitting unit 11 uses a 1310 nm DFB laser.

[0067] The spatial coupling unit 12 is used to receive the horizontally polarized light output by the laser emitting unit 11, expand the mode field diameter of the horizontally polarized light output by the laser emitting unit 11, and change the polarization state of the horizontally polarized light output by the laser emitting unit 11 to convert it into vertically polarized light.

[0068] Of course, in other embodiments of the present invention, the laser emitting unit 11 may also use other types of lasers that are capable of outputting high-power laser light. The output laser light may be horizontally polarized light or mixed polarized light. When the laser emitting unit 11 outputs mixed polarized light, the spatial coupling unit 12 may filter out the horizontally polarized light in the mixed polarized light or convert it into vertically polarized light.

[0069] Specifically, the spatial coupling unit 12 includes a lens 121 , an isolator 122 and a wave plate 123 .

[0070] The lens 121 is disposed near the laser emitting unit 11 and is used to expand the mode field diameter of the horizontally polarized light output by the laser emitting unit 11. Here, the lens 121 is a spherical glass lens.

[0071] The wave plate 123 is disposed close to the optical chip 2 , and relevant parameters can be set by the wave plate 123 to convert the horizontally polarized light output by the laser emitting unit 11 into vertically polarized light output.

[0072] The isolator 122 is disposed between the lens 121 and the wave plate 123 .

[0073] The present invention further provides an optical module, which has the light emitting component as described in any one of the above embodiments.

[0074] In summary, the optical chip in the coupled optical path proposed by the present invention receives vertically polarized light at the end optically coupled with the output light of the laser source. Compared with the technical solution in the commonly used technology in which the optical chip receives and outputs horizontally polarized light, the spot conversion unit, the optical processing unit, and the waveguide for transmitting the optical signal in the optical chip transmit vertically polarized light rather than horizontally polarized light when the input optical power is large, which can greatly reduce the nonlinear loss caused by optical transmission in the optical chip. Increasing the thickness of the optical transmission waveguide can also further reduce the transmission loss of vertically polarized light, thereby improving the overall performance of the optical chip.

[0075] It should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation method can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0076] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. An optical emission component, characterized in that, The optical emission component includes an optical output unit and an optical chip; The optical output unit is used to output vertically polarized light; The optical chip is sequentially connected along the optical signal propagation direction through an optical transmission waveguide: a first coupling unit, an optical processing unit, and a second coupling unit; The first coupling unit is used to receive the vertically polarized light and output it after coupling the vertically polarized light; The optical processing unit is used to receive the coupled vertically polarized light, process the coupled vertically polarized light, and output the processed vertically polarized light; The second coupling unit is used to receive the processed vertically polarized light, couple the processed vertically polarized light, and output it outside the optical chip; The thickness of at least part of the optical transmission waveguide is greater than or equal to 250 nm.

2. The optical emission component according to claim 1, characterized in that, The optical chip further includes a beam splitting unit, and the beam splitting unit is connected to the output end of the first coupling unit and is used to split the coupled vertically polarized light into at least two paths for transmission, and the optical processing unit and the second coupling unit are connected on each transmission path.

3. The optical emission component according to claim 1, characterized in that The optical chip further includes a mode filtering unit, and the mode filtering unit is connected to the first coupling unit and the optical processing unit, and its input end is connected to the output end of the first coupling unit and is used to only allow vertically polarized light to pass through.

4. The optical emission component according to claim 1, characterized in that, The optical processing unit includes an optical modulator, and the optical modulator includes a modulation electrode and a modulation waveguide, and the modulation waveguide is connected to the optical transmission waveguide; The thickness of the modulation waveguide is set to be greater than or equal to 250 nm.

5. The optical emission component according to any one of claims 1-4, characterized in that, The optical transmission waveguide is a silicon nitride waveguide and / or a silicon waveguide.

6. The optical emission component according to claim 5, characterized in that When the optical transmission waveguide is a silicon nitride waveguide, the thickness of the optical transmission waveguide is set to be greater than or equal to 250 nm; when the optical transmission waveguide is a silicon waveguide, the thickness of the optical transmission waveguide is set to be greater than or equal to 265 nm.

7. The optical emission component according to claim 5, characterized in that When the optical transmission waveguide is a silicon nitride waveguide and a silicon waveguide, a waveguide conversion structure is provided at the connection between the silicon nitride waveguide and the silicon waveguide, and the waveguide conversion structure is used for optical coupling between the silicon nitride waveguide and the silicon waveguide.

8. The optical emission component according to claim 1, characterized in that The optical output unit includes a laser emission unit and a spatial coupling unit, the laser emission unit is used to output horizontally polarized light, and the spatial coupling unit is arranged between the laser emission unit and the optical chip and is used to receive the horizontally polarized light and change the polarization state of the horizontally polarized light and output the vertically polarized light.

9. The optical emission component according to claim 8, characterized in that, The spatial coupling unit includes a lens, an isolator, and a wave plate. The lens is arranged close to the laser emission unit, the wave plate is arranged close to the optical chip and is used to convert the horizontally polarized light into vertically polarized light for output; the isolator is arranged between the lens and the wave plate.

10. An optical module, characterized in that, The optical module has the optical emission component as described in any one of claims 1-9.

Images