O-band silicon-based heterogeneous integrated light emitting device and preparation method thereof

Abstract

The invention relates to an O-band silicon-based heterogeneous integrated light emitting device and a preparation method thereof, and belongs to the technical field of optical devices. The InP and lithium niobate materials are integrated on the silicon-based photon platform in a wafer bonding mode, alignment of active and passive devices is achieved through the photoetching process, the alignment problem does not need to be considered, large-scale production can be carried out in the wafer bonding mode, the cost of a single device can be reduced, and the production efficiency is improved. The integrated level is high, the cost is saved, and mass production is facilitated; the defects of lattice mismatch and thermal expansion coefficient mismatch of silicon, InP and lithium niobate materials of the silicon-based photon platform can be overcome through a BCB polymer auxiliary bonding technology or a low-temperature direct bonding technology, so that integration of different functional materials on the silicon-based photon platform is realized; mode matching between waveguides made of different materials is realized by designing a corresponding spot size converter structure.

Description

Technical Field

[0001] The present invention relates to the technical field of optical devices, and in particular to an O-band silicon-based heterogeneous integrated light emitting device and a preparation method thereof. Background Art

[0002] Although silicon-based photonic technology has great potential, it also faces some challenges. Silicon material is an indirect bandgap semiconductor with low direct light emission efficiency, so hybrid integration technology is needed to solve problems such as on-chip light source and light amplification. In addition, with the increasing demand for bandwidth, lithium niobate materials have received more and more attention due to their high electro-optical effect. Based on the low loss and high electro-optic coefficient of lithium niobate materials, high-speed electro-optic modulators based on thin-film lithium niobate (LN) have achieved ultra-high bandwidth 8-channel thin-film lithium niobate chips with >110GHz supporting single-wave 400G (3.2T DR8) applications. It has become a consensus to integrate different materials onto the same platform through wafer bonding to achieve systematic and multifunctional photonic integrated chips.

[0003] At present, the main ways to integrate other materials on silicon include micro-transfer printing, Flip-Chip and other methods. Among them, micro-transfer printing technology requires high-precision transfer equipment. Even so, the alignment between active and passive devices is still a technology that needs to be improved. Flip-Chip technology is not suitable for mass production because it requires active alignment of each channel. In addition, the silicon and InP and lithium niobate materials of the current silicon-based photonic platform have problems such as lattice mismatch and thermal expansion coefficient mismatch, and there is a refractive index mismatch between silicon and InP and lithium niobate materials. Summary of the invention

[0004] The object of the present invention is to overcome the shortcomings of the prior art and provide an O-band silicon-based heterogeneous integrated light emitting device and a preparation method thereof.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides an O-band silicon-based heterogeneous integrated light emitting device, characterized in that it includes a silicon-based photonic waveguide layer, an InP waveguide layer, a lithium niobate waveguide layer and a first insulating layer, wherein the first insulating layer is arranged on the upper surface of the silicon-based photonic waveguide layer, the InP waveguide layer and the lithium niobate waveguide layer are arranged on the upper surface of the first insulating layer, the silicon-based photonic waveguide layer and the InP waveguide layer are optically interconnected in a vertical evanescent wave coupling manner, and the silicon-based photonic waveguide layer and the lithium niobate waveguide layer are optically interconnected in a vertical evanescent wave coupling manner.

[0007] Preferably, a silicon-based straight waveguide is provided on the silicon-based photonic waveguide layer, and an InP straight waveguide and two InP tapered waveguides are provided on the InP waveguide layer. The two InP tapered waveguides are respectively provided on both sides of the straight waveguide, and the silicon-based straight waveguide overlaps with the InP straight waveguide and the two InP tapered waveguides in the direction of optical signal transmission.

[0008] Further preferably, the width of the silicon-based straight waveguide is 500-5000nm; the width of the InP straight waveguide is 2000-7000nm; the width of the InP tapered waveguide increases linearly from its tip to its tail end, the tail end of the InP tapered waveguide is connected to the InP straight waveguide, the tail end width of the InP tapered waveguide is equal to the width of the InP straight waveguide, and the tip width of the InP tapered waveguide is 100-500nm.

[0009] Further preferably, the length of the overlapping region between the silicon-based straight waveguide and the InP tapered waveguide in the optical signal transmission direction is 10 to 50,000 μm.

[0010] Further preferably, the InP straight waveguide and the two InP tapered waveguides are composed of a quantum well layer, a p-InP layer and a p-Contact layer which are sequentially arranged from bottom to top.

[0011] Further preferably, two silicon-based conical waveguides are provided on the silicon-based photonic waveguide layer, and the lithium niobate waveguide layer is provided with a lithium niobate straight waveguide and two lithium niobate conical waveguides located on both sides of the lithium niobate straight waveguide, and the silicon-based conical waveguide overlaps with the lithium niobate conical waveguide in a one-to-one correspondence in the transmission direction of the optical signal.

[0012] More preferably, the width of the silicon-based straight waveguide is 500-5000nm; the width of the lithium niobate straight waveguide is 500-5000nm; the width of the silicon-based tapered waveguide increases linearly from the tip to the tail end, the tip width of the silicon-based tapered waveguide is 100-300nm, the tail end of the silicon-based tapered waveguide is connected to the silicon-based straight waveguide, and the tail end width of the silicon-based tapered waveguide is equal to the width of the silicon-based straight waveguide; the width of the lithium niobate tapered waveguide increases linearly from the tip to the tail end, the tip width of the lithium niobate tapered waveguide is 100-500nm, the tail end of the lithium niobate tapered waveguide is connected to the lithium niobate straight waveguide, and the tail end width of the lithium niobate tapered waveguide is equal to the width of the lithium niobate straight waveguide.

[0013] Further preferably, the length of the overlapping region between the silicon-based tapered waveguide and the lithium niobate tapered waveguide in the optical signal transmission direction is 10 to 50,000 μm.

[0014] Preferably, the first insulating layer is a silicon dioxide layer, or a silicon dioxide layer and a BCB layer sequentially arranged from bottom to top.

[0015] Preferably, a base layer is arranged below the silicon-based photonic waveguide layer, and the base layer includes a BOX layer and a substrate layer which are arranged in sequence from top to bottom.

[0016] In a second aspect, the present invention provides a method for preparing an O-band silicon-based heterogeneous integrated light emitting device as described in the first aspect, comprising the following steps:

[0017] S1. Processing the silicon-based photonic waveguide layer to prepare silicon-based straight waveguides, silicon-based tapered waveguides, and silicon-based grating passive optical devices;

[0018] S2, preparing a first insulating layer on the silicon-based photonic waveguide layer processed in step S1;

[0019] S3, transferring the InP epitaxial layer and the lithium niobate thin film device layer to the side of the first insulating layer away from the silicon-based photonic waveguide layer in a substrate-upward manner, removing the substrate by substrate thinning and wet etching, and depositing silicon oxide cladding layers on the InP epitaxial layer and the lithium niobate thin film device layer respectively;

[0020] S4, preparing an InP waveguide layer, a lithium niobate waveguide layer, a P metal layer, an N metal layer and a metal contact layer.

[0021] Preferably, step S4 comprises:

[0022] A. opening a window in the cladding layer on the lithium niobate thin film device layer to expose the lithium niobate thin film device layer, processing the exposed lithium niobate thin film device layer to form a lithium niobate waveguide layer, depositing a silicon oxide cladding layer on the upper surface of the lithium niobate waveguide layer by thin film deposition technology, and preparing a metal contact layer on the corresponding area of ​​the silicon oxide cladding layer by evaporating metal and lift-off process;

[0023] B. Open a window in the cladding layer on the InP epitaxial layer to expose the InP epitaxial layer, process the exposed InP epitaxial layer to form an InP waveguide layer, and prepare a P metal layer and an N metal layer on the InP waveguide layer by metal evaporation and lift-off process.

[0024] In step S4, step A may be performed first, a silicon oxide cladding layer may be deposited on the metal contact layer using a thin film deposition technique, and then step B may be performed, and then a window may be opened in the cladding layer on the metal contact layer to expose the metal contact layer;

[0025] In step S4, step B may be performed first, and a silicon oxide cladding layer may be deposited on the P metal layer and the N metal layer using thin film deposition technology, followed by step A, and then windows may be opened in the cladding layer on the P metal layer and the N metal layer to expose the P metal layer and the N metal layer.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention realizes mode matching between waveguides made of different materials by designing a corresponding pattern spot converter structure.

[0028] The present invention integrates InP and lithium niobate materials on a silicon-based photonic waveguide layer by wafer bonding. The alignment of active and passive devices is achieved through a photolithography process, and there is no need to consider the alignment problem. Large-scale production can be carried out by wafer bonding, which can reduce the cost of a single device. It also has the advantages of high integration, cost savings, and convenience for mass production.

[0029] The present invention can overcome the defects of lattice mismatch and thermal expansion coefficient mismatch between silicon and InP and lithium niobate materials of the silicon-based photonic platform through BCB polymer-assisted bonding technology or direct bonding technology, thereby realizing the integration of different functional materials on the silicon-based photonic platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic plan view of an O-band silicon-based heterogeneous integrated light emitting device provided by the present invention;

[0031] Figure 2 A schematic diagram of a layered structure of a light emitting device provided in an embodiment in a region where an InP waveguide layer is provided;

[0032] Figure 3 A schematic diagram of a layered structure of a light emitting device provided in another embodiment in a region where an InP waveguide layer is provided;

[0033] Figure 4 A schematic diagram of the layered structure of a light emitting device provided in an embodiment in a region where a lithium niobate waveguide layer is provided;

[0034] Figure 5 A schematic diagram of the layered structure of a light emitting device provided in another embodiment in a region where a lithium niobate waveguide layer is provided.

[0035] In the figure, 1-silicon-based photonic waveguide layer, 11-silicon-based straight waveguide, 12-silicon-based tapered waveguide, 2-InP waveguide layer, 21-n-InP layer, 22-InP straight waveguide, 23-InP tapered waveguide, 24-quantum well layer, 25-p-InP layer, 26-p-Contact layer, 3-lithium niobate waveguide layer, 31-lithium niobate straight waveguide, 32-lithium niobate tapered waveguide, 4-first insulating layer, 41-BOX layer, 42-BCB layer, 5-base layer, 51-substrate layer, 52-BOX layer, 6-cladding layer, 7-P metal layer, 8-N metal layer, 9-metal contact layer. DETAILED DESCRIPTION

[0036] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0037] See also Figures 1 to 5 In a first aspect, the present invention provides an O-band silicon-based heterogeneous integrated light emitting device, comprising a silicon-based photonic waveguide layer 1, an InP waveguide layer 2, a lithium niobate waveguide layer 3 and a first insulating layer 4, wherein the first insulating layer 4 is disposed above the silicon-based photonic waveguide layer 1, the InP waveguide layer 2 and the lithium niobate waveguide layer 3 are disposed above the first insulating layer 4, the silicon-based photonic waveguide layer 1 and the InP waveguide layer 2 are optically interconnected by vertical evanescent wave coupling, and the silicon-based photonic waveguide layer 1 and the lithium niobate waveguide layer 3 are optically interconnected by vertical evanescent wave coupling.

[0038] In one embodiment, a silicon-based straight waveguide 11 is disposed on the silicon-based photonic waveguide layer 1, the InP waveguide layer 2 includes an n-InP layer 21, an InP straight waveguide 22 and two InP tapered waveguides 23 are disposed on the n-InP layer 21, the two InP tapered waveguides 23 are respectively disposed on both sides of the InP straight waveguide 22, and the silicon-based straight waveguide 11 overlaps with the InP straight waveguide 22 and the two InP tapered waveguides 23 in the direction of optical signal transmission.

[0039] In the present invention, the silicon-based straight waveguide 11 is respectively coupled with the InP straight waveguide 22 and two InP tapered waveguides 23 by vertical evanescent wave coupling to form a Si / InP spot mode converter and maintain mode matching. The silicon-based photonic waveguide layer 1 is optically interconnected with the InP waveguide layer 2 by vertical evanescent wave coupling through the Si / InP spot mode converter, thereby realizing functions such as light generation, detection, and amplification. The operating wavelength of the light emitting device described in the present invention can cover the O band.

[0040] Specifically, the width of the silicon-based straight waveguide 11 is 500-5000nm; the width of the InP straight waveguide 22 is 2000-7000nm; the width of the InP tapered waveguide 23 increases linearly from its tip to its tail, the tip width of the InP tapered waveguide 23 is 100-500nm, the tail end of the InP tapered waveguide 23 is connected to the InP straight waveguide 22, and the tail end width of the InP tapered waveguide 23 is equal to the width of the InP straight waveguide 23.

[0041] The length L1 of the overlapping region (ie, the coupling region) between the silicon-based straight waveguide 11 and the InP tapered waveguide 23 in the optical signal transmission direction is 10 to 50,000 μm.

[0042] Specifically, the InP straight waveguide 22 and the two InP tapered waveguides 23 are composed of a quantum well layer 24 , a p-InP layer 25 , and a p-Contact layer 26 which are sequentially arranged from bottom to top.

[0043] Specifically, the silicon-based photonic waveguide layer 1 is further provided with two silicon-based tapered waveguides 12, and the lithium niobate waveguide layer 3 is provided with a lithium niobate straight waveguide 31 and lithium niobate tapered waveguides 32 located on both sides of the lithium niobate straight waveguide 31, and the silicon-based tapered waveguide 12 and the lithium niobate tapered waveguide 32 overlap one by one in the direction of optical signal transmission.

[0044] In the present invention, the silicon-based tapered waveguide 12 is vertically evanescently coupled with the lithium niobate tapered waveguide 32 to form a Si / LN spot mode converter and maintain mode matching. The silicon-based photonic waveguide layer 1 is optically interconnected with the lithium niobate waveguide layer 3 through the Si / LN spot mode converter in a vertical evanescent wave coupling manner, thereby realizing a high-speed linear optical modulation function.

[0045] Specifically, the width of the silicon-based tapered waveguide 12 increases linearly from the tip to the tail, and the width of the silicon-based tapered waveguide 12 is 100-300nm. The tail of the silicon-based tapered waveguide 12 is connected to the silicon-based straight waveguide 11, and the width of the tail of the silicon-based tapered waveguide 12 is the same as the width of the silicon-based straight waveguide 11; the width of the lithium niobate straight waveguide 31 is 500-5000nm; the width of the lithium niobate tapered waveguide 32 increases linearly from the tip to the tail, and the width of the lithium niobate tapered waveguide 32 is 100-500nm. The tail of the lithium niobate tapered waveguide 32 is connected to the lithium niobate straight waveguide 31, and the width of the tail of the lithium niobate tapered waveguide 32 is the same as the width of the lithium niobate straight waveguide. The tip of the lithium niobate tapered waveguide 32 is opposite to the tip of the silicon-based tapered waveguide 12.

[0046] Specifically, the length L2 of the overlapping region (ie, the coupling region) of the silicon-based tapered waveguide 12 and the lithium niobate tapered waveguide 32 in the optical signal transmission direction is 10 to 50,000 μm.

[0047] The inventors have found through research that when L1 is 50-200 μm and L2 is 50-200 μm, a higher coupling efficiency can be achieved between the InP waveguide layer 2 , the lithium niobate waveguide layer 3 and the silicon-based photonic waveguide layer 1 .

[0048] Specifically, an N metal layer 8 is disposed on the n-InP layer 21 , and a P metal layer 7 is disposed on the p-Contact layer 26 .

[0049] Specifically, a cladding 6 is provided on the upper surface of the lithium niobate waveguide layer 3 , and a cladding 6 is provided on the upper surface of the n-InP layer 21 excluding the N metal layer 8 region. The cladding 6 also wraps around the side surfaces of the quantum well layer 24 , the p-InP layer 25 and the p-Contact layer 26 .

[0050] The material of the cladding layer 6 can be silicon dioxide or benzocyclobutene, and the thickness of the cladding layer 6 is 1 to 3 μm.

[0051] The total thickness H of the silicon-based photonic waveguide layer 1 is not less than 400 nm (preferably 400-800 nm), the thickness h1 of the silicon-based straight waveguide 11 is 220-400 nm, and the thickness h2 of the silicon-based tapered waveguide 12 is 220-400 nm.

[0052] The thickness of the n-InP layer 21 is 50 to 300 nm, the thickness of the quantum well layer 24 is 100 to 500 nm, the thickness of the p-InP layer 25 is 1500 to 2000 nm, the thickness of the p-Contact layer 26 is 50 to 300 nm, the total thickness of the lithium niobate waveguide layer 3 is 360 to 600 nm, the thickness of the lithium niobate straight waveguide 31 is 180 to 300 nm, and the thickness of the lithium niobate tapered waveguide 32 is 180 to 300 nm.

[0053] In the present invention, the total thickness of the silicon-based photonic waveguide layer 1 can be selected from 450nm, 500nm, 600nm, 700nm, 800nm ​​or a range consisting of two groups of values ​​therein, and the thicknesses of the silicon-based straight waveguide 11 and the silicon-based tapered waveguide 12 can be independently selected from 220nm, 250nm, 300nm, 350nm or a range consisting of two groups of values ​​therein. The InP waveguide layer 2 can be coupled with the silicon-based photonic waveguide layer 1 having a thickness greater than 400nm with higher efficiency.

[0054] In one embodiment, the first insulating layer 4 may be a silicon dioxide layer 41, or may be composed of a silicon dioxide layer 41 and a BCB layer 42, wherein the thickness of the silicon dioxide layer 41 is 10-50 nm, and the thickness of the BCB layer 42 is 10-50 nm. In the present invention, the material of the BCB layer is benzocyclobutene.

[0055] In one embodiment, a base layer 5 is disposed below the silicon-based photonic waveguide layer 1 , and the base layer 5 includes a BOX layer 51 and a substrate layer 52 which are sequentially disposed from top to bottom.

[0056] Specifically, the material of the BOX layer 51 may be silicon dioxide.

[0057] Specifically, the material of the substrate layer 52 may be silicon.

[0058] In a second aspect, the present invention provides a method for preparing an O-band silicon-based heterogeneous integrated light emitting device as described in the first aspect, comprising the following steps:

[0059] S1, processing the silicon-based photonic waveguide layer 1 to prepare a silicon-based straight waveguide 11, a silicon-based tapered waveguide 12, and a silicon-based grating passive optical device (not shown in the figure);

[0060] S2, preparing a first insulating layer 4 on the silicon-based photonic waveguide layer 1 processed in step S1;

[0061] S3, transferring the InP epitaxial layer and the lithium niobate thin film device layer to the side of the first insulating layer 4 away from the silicon-based photonic waveguide layer 1 with the substrate facing upward, removing the substrate by substrate thinning and wet etching, and depositing silicon oxide cladding layers on the InP epitaxial layer and the lithium niobate thin film device layer respectively;

[0062] S4, preparing an InP waveguide layer 2, a lithium niobate waveguide layer 3, a P metal layer 7, an N metal layer 8 and a metal contact layer 9.

[0063] Step S4 includes:

[0064] A. A window is opened in the cladding layer on the lithium niobate thin film device layer to expose the lithium niobate thin film device layer, and the exposed lithium niobate thin film device layer is processed to form a lithium niobate waveguide layer 3, and a silicon oxide cladding layer is deposited on the upper surface of the lithium niobate waveguide layer 3 by thin film deposition technology, and a metal contact layer 9 is prepared on the corresponding area of ​​the silicon oxide cladding layer by evaporating metal and lift-off process;

[0065] B. A window is opened in the cladding layer on the InP epitaxial layer to expose the InP epitaxial layer, and the exposed InP epitaxial layer is processed to form an InP waveguide layer 2. A P metal layer 7 and an N metal layer 8 are prepared on the InP waveguide layer 2 by metal evaporation and lift-off process.

[0066] In step S4, step A may be performed first, and a silicon oxide cladding layer may be deposited on the metal contact layer 9 by using a thin film deposition technique, and then step B may be performed, and then a window may be opened in the cladding layer on the metal contact layer 9 to expose the metal contact layer 9;

[0067] In step S4, step B may be implemented first, and a silicon oxide cladding layer may be deposited on the P metal layer 7 and the N metal layer 8 using thin film deposition technology, followed by step A, and then windows may be opened in the cladding layer on the P metal layer 7 and the N metal layer 8 to expose the P metal layer 7 and the N metal layer 8.

[0068] In one embodiment, step S2 includes: preparing a BOX layer 41 on the upper surface of the silicon-based photonic waveguide layer 1, depositing a silicon dioxide thin film on the upper surface of the silicon-based photonic waveguide layer 1 using a thin film deposition method, and then polishing the formed silicon dioxide thin film to be flat using a chemical mechanical polishing technique to form the BOX layer 41.

[0069] Specifically, step S2 further includes: spin coating benzocyclobutene on the upper surface of the BOX layer 41 , and forming the BCB layer 42 through curing.

[0070] The present invention integrates InP and lithium niobate materials on a silicon-based photonic waveguide layer by wafer bonding. The alignment of active and passive devices is achieved through a photolithography process, and there is no need to consider the alignment problem. Large-scale production can be carried out by wafer bonding, which can reduce the cost of a single device. It also has the advantages of high integration, cost savings, and convenience for mass production.

[0071] The present invention can overcome the defects of lattice mismatch and thermal expansion coefficient mismatch between silicon and InP and lithium niobate materials of the silicon-based photonic platform through BCB polymer-assisted bonding technology or direct bonding technology, thereby realizing the integration of different functional materials on the silicon-based photonic platform.

[0072] In one embodiment, in step S3, the cladding 6 is prepared by a thin film deposition method or a spin coating method. For example, the material of the cladding 6 is silicon dioxide, and silicon dioxide is deposited on the outer surface of the InP waveguide layer 2 and the lithium niobate waveguide layer 3 by a thin film deposition method to form the cladding 6; for another example, the material of the cladding 6 is benzocyclobutene, and benzocyclobutene is spin-coated on the outer surface of the InP waveguide layer 2 and the lithium niobate waveguide layer 3 by a spin coating method, and the cladding 6 is formed after curing.

[0073] In one embodiment, before step S1 , the method further includes: preparing a BOX layer 51 on the upper surface of the substrate layer 52 , and preparing a silicon-based photonic waveguide layer 1 on the upper surface of the BOX layer 51 .

[0074] Specifically, the BOX layer 51 may be prepared by a thin film deposition method.

[0075] In the description of the present invention, it should be noted that the terms "first", "second" and "third" are only used for descriptive purposes and cannot be understood as indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include at least one of the features. All directional indicators (such as up and down) in the present invention are only used to explain the relative position relationship, movement status, etc. between the various parts under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0076] In the description of the present invention, it should also be noted that the terms "include", "have" and any variations thereof are intended to cover non-exclusive inclusions.

[0077] For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An O-band silicon-based heterogeneous integrated light emitting device, characterized in that: The invention comprises a silicon-based photon waveguide layer, an InP waveguide layer, a lithium niobate waveguide layer and a first insulating layer, wherein the first insulating layer is arranged on the upper surface of the silicon-based photon waveguide layer, the InP waveguide layer and the lithium niobate waveguide layer are arranged on the upper surface of the first insulating layer, the silicon-based photon waveguide layer and the InP waveguide layer are optically interconnected by vertical evanescent wave coupling, and the silicon-based photon waveguide layer and the lithium niobate waveguide layer are optically interconnected by vertical evanescent wave coupling.

2. The O-band silicon-based heterogeneous integrated light emitting device according to claim 1, characterized in that: A silicon-based straight waveguide is arranged on the silicon-based photonic waveguide layer, and an InP straight waveguide and two InP tapered waveguides are arranged on the InP waveguide layer. The two InP tapered waveguides are respectively arranged on both sides of the straight waveguide, and the silicon-based straight waveguide overlaps with the InP straight waveguide and the two InP tapered waveguides in the direction of optical signal transmission.

3. The O-band silicon-based heterogeneous integrated light emitting device as claimed in claim 2, characterized in that: The width of the silicon-based straight waveguide is 500-5000nm; the width of the InP straight waveguide is 2000-7000nm; the width of the InP tapered waveguide increases linearly from its tip to its tail end, the tail end of the InP tapered waveguide is connected to the InP straight waveguide, the tail end width of the InP tapered waveguide is equal to the width of the InP straight waveguide, and the tip width of the InP tapered waveguide is 100-500nm.

4. The O-band silicon-based heterogeneous integrated light emitting device as claimed in claim 2, characterized in that: The length of the overlapping region between the silicon-based straight waveguide and the InP straight waveguide in the optical signal transmission direction is 10 to 50,000 μm, and the length of the overlapping region between the silicon-based straight waveguide and the InP tapered waveguide in the optical signal transmission direction is 10 to 50,000 μm.

5. The O-band silicon-based heterogeneous integrated light emitting device as claimed in claim 2, characterized in that: The InP straight waveguide and the two InP tapered waveguides are composed of a quantum well layer, a p-InP layer and a p-Contact layer which are arranged in sequence from bottom to top.

6. The O-band silicon-based heterogeneous integrated light emitting device as claimed in claim 2, characterized in that: Two silicon-based tapered waveguides are also arranged on the silicon-based photonic waveguide layer, and the lithium niobate waveguide layer is provided with a lithium niobate straight waveguide and two lithium niobate tapered waveguides respectively located on both sides of the lithium niobate straight waveguide. The silicon-based tapered waveguide and the lithium niobate tapered waveguide overlap one-to-one in the direction of optical signal transmission.

7. The O-band silicon-based heterogeneous integrated light emitting device as claimed in claim 6, characterized in that: The width of the lithium niobate straight waveguide is 500-5000nm; the width of the silicon-based conical waveguide increases linearly from the tip to the tail end, the tip width of the silicon-based conical waveguide is 100-300nm, the tail end of the silicon-based conical waveguide is connected to the silicon-based straight waveguide, and the tail end width of the silicon-based conical waveguide is equal to the width of the silicon-based straight waveguide; the width of the lithium niobate conical waveguide increases linearly from the tip to the tail end, the tip width of the lithium niobate conical waveguide is 100-500nm, the tail end of the lithium niobate conical waveguide is connected to the lithium niobate straight waveguide, and the tail end width of the lithium niobate conical waveguide is equal to the width of the lithium niobate straight waveguide.

8. The O-band silicon-based heterogeneous integrated light emitting device as claimed in claim 7, characterized in that: The length of the overlapping region between the silicon-based tapered waveguide and the lithium niobate tapered waveguide in the optical signal transmission direction is 10 to 50,000 μm.

9. The O-band silicon-based heterogeneous integrated light emitting device according to claim 1, characterized in that: The first insulating layer includes a silicon dioxide layer, or a silicon dioxide layer and a BCB layer sequentially arranged from bottom to top.

10. A method for preparing an O-band silicon-based heterogeneous integrated light emitting device as claimed in any one of claims 1 to 9, characterized in that: The steps include: S1. Processing the silicon-based photonic waveguide layer to prepare silicon-based straight waveguides, silicon-based tapered waveguides, and silicon-based grating passive optical devices; S2, preparing a first insulating layer on the silicon-based photonic waveguide layer processed in step S1; S3, transferring the InP epitaxial layer and the lithium niobate thin film device layer to the side of the first insulating layer away from the silicon-based photonic waveguide layer in a substrate-upward manner, removing the substrate by substrate thinning and wet etching, and depositing silicon oxide cladding layers on the InP epitaxial layer and the lithium niobate thin film device layer respectively; S4, preparing an InP waveguide layer, a lithium niobate waveguide layer, a P metal layer, an N metal layer and a metal contact layer; Preferably, step S4 comprises: A. opening a window in the cladding layer on the lithium niobate thin film device layer to expose the lithium niobate thin film device layer, processing the exposed lithium niobate thin film device layer to form a lithium niobate waveguide layer, depositing a silicon oxide cladding layer on the upper surface of the lithium niobate waveguide layer by thin film deposition technology, and preparing a metal contact layer on the corresponding area of ​​the silicon oxide cladding layer by evaporating metal and lift-off process; B. Opening a window in the cladding layer on the InP epitaxial layer to expose the InP epitaxial layer, processing the exposed InP epitaxial layer to form an InP waveguide layer, and preparing a P metal layer and an N metal layer on the InP waveguide layer by evaporating metal and a lift-off process; In step S4, step A is first implemented, and a silicon oxide cladding layer is deposited on the metal contact layer using a thin film deposition technique, and then step B is implemented, and then a window is opened in the cladding layer on the metal contact layer to expose the metal contact layer; or step B is first implemented, and a silicon oxide cladding layer is deposited on the P metal layer and the N metal layer using a thin film deposition technique, and then step A is implemented, and then a window is opened in the cladding layer on the P metal layer and the N metal layer to expose the P metal layer and the N metal layer.

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