Polarization-independent light polarization conversion device and optical chip integration structure

Abstract

The invention provides a polarization-independent light polarization conversion device which comprises an input plano-convex lens, a polarization beam splitter, a right-angle reflecting prism, a half-wave plate, a delay prism and an output plano-convex lens. The input plano-convex lens is used for coupling input light into the polarization beam splitter; the polarization beam splitter is used for transmitting horizontal polarized light in input light and vertically reflecting vertical polarized light in the input light, the vertical polarized light completes 90-degree deflection in the light propagation direction through the right-angle reflecting prism, and the vertical polarized light and the horizontal polarized light form two polarization branches. Wherein one polarization branch is converted into a state parallel to the other polarization branch through the half-wave plate; the delay prism is used for completing phase compensation between the two polarization branches; and the output plano-convex lens is used for completing beam combination output of the two polarization branches. The optical chip integrated structure disclosed by the invention comprises an optical chip and the light polarization conversion device irrelevant to polarization.

Description

Technical Field

[0001] The present invention relates to the technical field of light polarization, and in particular to a polarization-independent light polarization conversion device and an optical chip integrated structure. Background Art

[0002] Lithium niobate material has the advantages of high electro-optic coefficient and low loss in C band, and is the preferred material for electro-optic modulators. At the same time, the emergence of lithium niobate thin film and the breakthrough of etching technology have solved the problem of small refractive index difference of traditional lithium niobate bulk material waveguide, which can achieve stronger mode confinement and is a solution for the next generation of photonic integrated circuits. Modulators based on thin film lithium niobate materials have great application value in the future field of optical communications as the next generation of low modulation voltage, high modulation bandwidth and low insertion loss modulators. However, the current technically mature lithium niobate electro-optic modulator can only work effectively when the optical signal has a single polarization state (TE mode or TM mode). Therefore, polarization-maintaining fiber is often used to connect to lithium niobate electro-optic modulators. However, due to the high cost of polarization-maintaining fiber and the fact that the longer polarization-maintaining fiber is easily affected by ambient temperature vibration, the polarization state of the output light of the polarization-maintaining fiber changes, which affects the efficient operation of the lithium niobate electro-optic modulator and greatly limits the application of lithium niobate electro-optic modulators. Summary of the invention

[0003] In order to solve the technical problems existing in the background technology, the present invention proposes a polarization-independent optical polarization conversion device and an optical chip integrated structure.

[0004] The present invention provides a polarization-independent optical polarization conversion device, comprising: an input plano-convex lens, a polarization beam splitter, a right-angle reflection prism, a half-wave plate, a delay prism and an output plano-convex lens;

[0005] The input plano-convex lens is used to couple the input light into the polarization beam splitter;

[0006] A polarization beam splitter, a right-angle reflection prism, a half-wave plate, and a delay prism are arranged between an input plano-convex lens and an output plano-convex lens; the polarization beam splitter is used to transmit horizontal polarized light in the input light and vertically reflect vertical polarized light in the input light, and the vertical polarized light is deflected 90 degrees in the light propagation direction through the right-angle reflection prism, and the vertical polarized light and the horizontal polarized light transmitted by the polarization beam splitter form two polarization branches, one of which is converted into a state parallel to the other polarization branch through the half-wave plate;

[0007] The delay prism is used to complete the phase compensation between the two polarization branches;

[0008] The output plano-convex lens is used to complete the beam combining output of the two polarization branches.

[0009] Preferably, the input light is decomposed into two components, horizontal polarized light and vertical polarized light, according to the polarization characteristics of the light. The input light is coupled into a polarization beam splitter through an input plano-convex lens. The polarization beam splitter transmits the horizontal polarized light in the input light, and the horizontal polarized light is phase compensated through a delay prism; the polarization beam splitter vertically reflects the vertical polarized light in the input light, and the vertical polarized light is deflected 90 degrees in the direction of light propagation through a right-angle reflection prism, and then converted into horizontal polarized light through a half-wave plate; the horizontal polarized light output by the delay prism and the horizontal polarized light output by the half-wave plate are combined and output through an output plano-convex lens.

[0010] Preferably, both the input plano-convex lens and the output plano-convex lens are plano-convex lenses. The input plano-convex lens converts the input light at the left focus of the lens into parallel light and transmits it in the polarization beam splitter, right-angle reflection prism, half-wave plate and delay prism. The output plano-convex lens couples the parallel light transmitted to the lens to the output at the right focus of the lens.

[0011] Preferably, the polarization beam splitter is set to transmit an incident horizontally polarized light beam and reflect an incident vertically polarized light beam.

[0012] Preferably, the angle between the optical axis direction of the half wave plate and the polarization direction of the incident linear polarized light is 45 degrees, so that the polarization direction of the incident linear polarized light is rotated by 90 degrees.

[0013] Preferably, the input light is transmitted through the polarization beam splitter, the time-delay prism and the output plano-convex lens to the right focus of the output plano-convex lens at a transmission phase of The input light passes through the polarization beam splitter, right-angle reflection prism, half-wave plate and output plano-convex lens, and the transmission phase of the light to the right focus of the output plano-convex lens is: The delay prism is used to compensate the phase difference between the two optical paths, so that

[0014] Preferably, the installation positions of the half wave plate and the delay prism are interchanged to realize the combined beam output of vertical polarized light. At this time, the input light is coupled into the polarization beam splitter through the input plano-convex lens, and the polarization beam splitter transmits the horizontal polarized light in the input light, and the horizontal polarized light is converted into vertical polarized light through the half wave plate; the polarization beam splitter vertically reflects the vertical polarized light in the input light, and the vertical polarized light is deflected 90 degrees in the direction of light propagation through the right-angle reflection prism, and then phase compensated through the delay prism; the vertical polarized light output by the delay prism and the vertical polarized light output by the half wave plate are combined and output through the output plano-convex lens.

[0015] The present invention discloses an optical chip integrated structure, comprising: an optical chip and an optical polarization conversion device, wherein the optical polarization conversion device is the polarization-independent optical polarization conversion device described above, and optical signals are interconnected between the optical polarization conversion device and the optical chip.

[0016] Preferably, the optical polarization conversion device and the optical chip are interconnected by optical signals via a first output optical fiber.

[0017] Preferably, the optical polarization conversion device is packaged by a first tube shell, the optical chip is packaged by a second tube shell, one end of the first output optical fiber is located at the optical signal output end of the optical polarization conversion device and is packaged together with the optical polarization conversion device in the first tube shell, and the other end of the first output optical fiber is located at the optical signal input end of the optical chip and is packaged together with the optical chip in the second tube shell.

[0018] Preferably, it further comprises an input optical fiber connected to the optical polarization conversion device to input light to the optical polarization conversion device, and a second output optical fiber connected to the optical chip to output light.

[0019] Preferably, the input optical fiber is located at the optical signal input end of the optical polarization conversion device and is packaged together with the optical polarization conversion device in a first tube shell, and the second output optical fiber is located at the optical signal output end of the optical chip and is packaged together with the optical chip in a second tube shell.

[0020] Preferably, the input optical fiber is an ordinary single-mode optical fiber, the first output optical fiber is a polarization-maintaining optical fiber, and the second output optical fiber is an ordinary single-mode optical fiber or a polarization-maintaining optical fiber; and the optical chip is a single-polarization input and output optical chip.

[0021] Preferably, the optical polarization conversion device and the optical chip are co-packaged through a third tube shell, and the input end face of the optical chip is located at the right focus of the output plano-convex lens.

[0022] The present invention can convert random polarized light input from an ordinary single-mode optical fiber into a single linearly polarized light adapted to an ordinary lithium niobate electro-optical modulator. The intensity of the linearly polarized light is not affected by changes in the polarization state of the input light. Compared with the prior art, the present invention has the following advantages:

[0023] The characteristics and advantages of the present invention are:

[0024] 1. The present invention uses a polarization beam splitter and a half-wave plate to convert input light of any polarization state into linearly polarized light output, and the polarization state of the output linearly polarized light is independent of the polarization state of the input light.

[0025] 2. The present invention uses a plano-convex lens for input and output light coupling. The plano-convex lens is a polarization-independent device that can couple input light of any polarization state and has a wider range of applications.

[0026] 3. The delay prism of the present invention completes the phase compensation between the two polarization branches, so that the output light intensity is independent of the polarization state of the input light.

[0027] 4. The present invention couples through input and output plano-convex lenses. Optical fibers or optical chips can be placed at the input and output focal points. Fiber interconnection or co-packaged internal interconnection with subsequent optical chips can be performed, which is flexible to use and easy to integrate.

[0028] 5. The present invention can realize the switching of the polarization state of the output linear polarized light between horizontal polarization and vertical polarization by exchanging the installation positions of the half wave plate and the delay prism, and is flexible to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic structural diagram of a polarization-independent optical polarization conversion device proposed by the present invention;

[0030] Figure 2 A polarized light distribution diagram in a polarization-independent optical polarization conversion device proposed by the present invention;

[0031] Figure 3 A schematic diagram of the connection between a polarization-independent optical polarization conversion device and an independently packaged optical chip proposed by the present invention;

[0032] Figure 4 This is a schematic diagram of the co-packaging connection between the polarization-independent optical polarization conversion device and the optical chip proposed by the present invention. DETAILED DESCRIPTION

[0033] Reference Figure 1 The polarization-independent optical polarization conversion device proposed in the present invention comprises: an input plano-convex lens 1, a polarization beam splitter 2, a right-angle reflection prism 3, a half-wave plate 4, a delay prism 5 and an output plano-convex lens 6. The input light is decomposed into two components, horizontal polarization light and vertical polarization light, according to the polarization characteristics of the light. The input light is coupled into the polarization beam splitter 2 through the input plano-convex lens 1. The polarization beam splitter 2 transmits the horizontal polarization light in the input light, and the horizontal polarization light passes through the delay prism 5 for phase compensation; the polarization beam splitter 2 vertically reflects the vertical polarization light in the input light, and the vertical polarization light passes through the right-angle reflection prism 3 to complete the 90-degree deflection of the light propagation direction, and then passes through the half-wave plate 4 to convert it into horizontal polarization light; the horizontal polarization light output by the delay prism 5 and the horizontal polarization light output by the half-wave plate 4 pass through the output plano-convex lens 6 to complete the combined output, thereby converting the input random polarization light into a single linear polarization light, and the intensity of the linear polarization light is not affected by the change of the polarization state of the input light.

[0034] The input plano-convex lens 1 and the output plano-convex lens 6 are both plano-convex lenses. The input plano-convex lens 1 converts the input light at the left focus of the lens into parallel light and transmits it in the polarization beam splitter 2, the right-angle reflection prism 3, the half-wave plate 4 and the delay prism 5. The output plano-convex lens 6 couples the parallel light transmitted to the lens to the output at the right focus of the lens.

[0035] The polarization beam splitter 2 is set to transmit the incident horizontal polarization light beam and reflect the vertical polarization light beam.

[0036] The angle between the optical axis direction of the half-wave plate and the polarization direction of the incident vertical polarized light is 45 degrees, so that the polarization direction of the incident vertical polarized light is rotated 90 degrees and horizontal polarized light is output.

[0037] The input light passes through the polarization beam splitter 2, the delay prism 5 and the output plano-convex lens 6, and the transmission phase of the light to the right focus of the output plano-convex lens 6 is: The input light passes through the polarization beam splitter 2, the right-angle reflection prism 3, the half-wave plate 4 and the output plano-convex lens 6, and the transmission phase of the light to the right focus of the output plano-convex lens 6 is: The delay prism 5 is used to compensate the phase difference between the two optical paths, so that

[0038] In addition, the present invention can also realize vertical polarized light beam combination output by exchanging the installation positions of the above-mentioned half wave plate 4 and the delay prism 5. Specifically, the input light is decomposed into two components, horizontal polarized light and vertical polarized light, according to the polarization characteristics of the light. The input light is coupled into the polarization beam splitter 2 through the input plano-convex lens 1. The polarization beam splitter 2 transmits the horizontal polarized light in the input light, and the horizontal polarized light is converted into vertical polarized light through the half wave plate 4; the polarization beam splitter 2 vertically reflects the vertical polarized light in the input light, and the vertical polarized light is deflected 90 degrees in the light propagation direction through the right-angle reflection prism 3, and then phase compensated through the delay prism 5; the vertical polarized light output by the delay prism 5 and the vertical polarized light output by the half wave plate 4 are combined and output through the output plano-convex lens 6.

[0039] The working principle of the device of the present invention is explained below with the first embodiment

[0040] Embodiment 1

[0041] The device of the present invention is packaged together with the input optical fiber 71, the first output optical fiber 72 and the first tube shell 81. Figure 2 The input optical fiber 71 is a common single-mode optical fiber, and the first output optical fiber 72 is a polarization-maintaining optical fiber. The polarization distribution of the optical signal is shown in FIG. Figure 2 As shown in the figure, "·" represents vertical polarized light and "|" represents horizontal polarized light. The optical end face of the input optical fiber 71 is located at the left focus of the input plano-convex lens 1. The polarization state of the output light of the input optical fiber 71 will change with the influence of temperature vibration and the like. At any time, the angle between the polarization direction of the output light of the input optical fiber 71 and the optical axis of the polarization beam splitter 2 is set to α, the output light amplitude is E0, and the intensity is At this time, the outgoing light is decomposed into the horizontal polarization amplitude E H The amplitude E of the vertically polarized light V They are:

[0042] E H =E0cosα (1)

[0043] E V =E0sinα (2)

[0044] The polarization beam splitter 2 transmits the horizontal polarized light in the input light, and the horizontal polarized light passes through the delay prism 5 for phase compensation. The polarization beam splitter 2 vertically reflects the vertical polarized light in the input light, and the vertical polarized light passes through the right-angle reflection prism 3 to complete a 90-degree deflection in the light propagation direction, and then passes through the half-wave plate 4 to convert it into horizontal polarized light. The angle between the optical axis direction of the half-wave plate and the polarization direction of the incident vertical polarized light is 45 degrees, so that the polarization direction of the incident vertical polarized light is rotated 90 degrees, and horizontal polarized light is output. The horizontal polarized light output by the delay prism 5 and the horizontal polarized light output by the half-wave plate 4 are combined and output through the output plano-convex lens 6, and the two output lights are superimposed at the right focus of the output plano-convex lens 6. The light intensity I at the focus can be expressed as:

[0045]

[0046] Wherein, δ is the inherent phase difference of the two optical transmission paths. The transmission phase of the output light from the input optical fiber 71 is transmitted to the right focus of the output plano-convex lens 6 through the polarization beam splitter 2, the delay prism 5 and the output plano-convex lens 6. The outgoing light from the input optical fiber 71 passes through the polarization beam splitter 2, the right-angle reflection prism 3, the half-wave plate 4 and the output plano-convex lens 6, and the transmission phase of the transmission to the right focus of the output plano-convex lens 6 is The delay prism 5 is used to compensate the phase difference between the two output lights, so that That is, δ = π / 2, substituting it into formula (3) yields:

[0047]

[0048] At this time, the output light intensity is the same as the input light intensity, and the output light intensity is independent of the input light polarization direction angle α, that is, the output light intensity is independent of the input light polarization. An ordinary single-mode optical fiber without polarization maintenance can be used as the input end. The output light polarization state is a single linear polarization state (horizontal polarization state), which is easy to couple with a single polarization input device and has an output polarization conversion function that is independent of the input polarization.

[0049] There are two ways of interconnecting the device of the present invention with the subsequent optical chip:

[0050] Interconnection method 1: The device of the present invention can be independently packaged and interconnected with an optical chip with independent package through a polarization-maintaining optical fiber, such as Figure 3As shown. The device of the present invention is independently packaged by the input optical fiber 71, the first output optical fiber 72 and the first tube shell 81. The optical chip 9 is independently packaged by the first output optical fiber 72, the second output optical fiber 73 and the second tube shell 82. The optical chip 9 is a single polarization input and output optical chip. The optical signal between the device of the present invention and the optical chip 9 is interconnected by the first output optical fiber 72. The input optical fiber 71 is an ordinary single-mode optical fiber, the first output optical fiber 72 is a polarization-maintaining optical fiber, and the second output optical fiber 73 is an ordinary single-mode optical fiber or a polarization-maintaining optical fiber.

[0051] Interconnection method 2: The device of the present invention can also be co-packaged with an optical chip, and internal optical interconnection is performed through an output plano-convex lens 6, such as Figure 4 The device of the present invention is co-packaged with an optical chip 9, an input optical fiber 71, a third output optical fiber 74, and a third tube shell 83. The optical chip 9 is a single polarization input and output optical chip, and the input end face of the optical chip 9 is located at the right focus of the output plano-convex lens 6. The input optical fiber 71 is an ordinary single-mode optical fiber, and the third output optical fiber 74 is an ordinary single-mode optical fiber or a polarization-maintaining optical fiber.

[0052] The present invention discloses an optical chip integrated structure, comprising: an optical chip 9 and an optical polarization conversion device, wherein the optical polarization conversion device is the polarization-independent optical polarization conversion device described above, and optical signals are interconnected between the optical polarization conversion device and the optical chip 9.

[0053] Furthermore, the optical polarization conversion device and the optical chip 9 are interconnected by optical signals through the first output optical fiber 72, such as Figure 3 or the optical polarization conversion device and the optical chip 9 are co-packaged through a third tube shell 83, and the input end face of the optical chip 9 is located at the right focus of the output plano-convex lens 6, as shown Figure 4 shown.

[0054] Reference Figure 3 The optical polarization conversion device is packaged by a first tube shell 81, and the optical chip 9 is packaged by a second tube shell 82. One end of the first output optical fiber 72 is located at the optical signal output end of the optical polarization conversion device and is packaged together with the optical polarization conversion device in the first tube shell 81. The other end of the first output optical fiber 72 is located at the optical signal input end of the optical chip 9 and is packaged together with the optical chip 9 in the second tube shell 82.

[0055] Reference Figure 3 , further, it also includes an input optical fiber 71 connected to the optical polarization conversion device to input light to the optical polarization conversion device, and a second output optical fiber 73 connected to the optical chip 9 to output light, specifically: the input optical fiber 71 is located at the optical signal input end of the optical polarization conversion device and is packaged together with the optical polarization conversion device in a first tube shell 81, and the second output optical fiber 73 is located at the optical signal output end of the optical chip 9 and is packaged together with the optical chip 9 in a second tube shell 82;

[0056] The input optical fiber 71 in the present invention is a common single-mode optical fiber, the first output optical fiber 72 is a polarization-maintaining optical fiber, and the second output optical fiber 73 is a common single-mode optical fiber or a polarization-maintaining optical fiber; the optical chip 9 is a single-polarization input and output optical chip.

[0057] In summary, the present invention can convert the random polarized light input by ordinary single-mode optical fiber into a single linear polarized light adapted to the ordinary lithium niobate electro-optical modulator. The intensity of the linear polarized light is not affected by the change of the polarization state of the input light. Compared with the prior art, the present invention has the following advantages:

[0058] The characteristics and advantages of the present invention are:

[0059] 1. The present invention uses a polarization beam splitter 2 and a half wave plate 4 to convert input light of any polarization state into linearly polarized light output, and the polarization state of the output linearly polarized light is independent of the polarization state of the input light.

[0060] 2. The present invention uses a plano-convex lens for input and output light coupling. The plano-convex lens is a polarization-independent device that can couple input light of any polarization state and has a wider range of applications.

[0061] 3. The delay prism 5 of the present invention completes the phase compensation between the two polarization branches, so that the output light intensity is independent of the polarization state of the input light.

[0062] 4. The present invention couples through input and output plano-convex lenses 1 and 6. Optical fibers or optical chips can be placed at the input and output focal points, and optical fiber interconnection or co-packaged internal interconnection with subsequent optical chips can be performed. It is flexible to use and easy to integrate.

[0063] 5. The present invention can realize the switching of the polarization state of the output linear polarized light between horizontal polarization and vertical polarization by exchanging the installation positions of the half wave plate 4 and the delay prism 5, and is flexible to use.

[0064] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A polarization-independent optical polarization conversion device, characterized in that: include: An input plano-convex lens (1), a polarization beam splitter (2), a right-angle reflection prism (3), a half-wave plate (4), a delay prism (5) and an output plano-convex lens (6); The input plano-convex lens (1) is used to couple the input light into the polarization beam splitter (2); A polarization beam splitter (2), a right-angle reflection prism (3), a half-wave plate (4), and a delay prism (5) are arranged between an input plano-convex lens (1) and an output plano-convex lens (6); the polarization beam splitter (2) is used to transmit horizontal polarized light in the input light and vertically reflect vertical polarized light in the input light, and the vertical polarized light is deflected 90 degrees in the light propagation direction via the right-angle reflection prism (3), and the vertical polarized light and the horizontal polarized light transmitted by the polarization beam splitter (2) form two polarization branches, one of which is converted into a state parallel to the other polarization branch via the half-wave plate (4); The delay prism (5) is used to complete the phase compensation between the two polarization branches; The output plano-convex lens (6) is used to complete the beam combining output of the two polarization branches.

2. The polarization-independent optical polarization conversion device according to claim 1 is characterized in that the input light is coupled into the polarization beam splitter (2) through an input plano-convex lens (1); the polarization beam splitter (2) transmits the horizontal polarized light in the input light, and the horizontal polarized light is phase-compensated through a delay prism (5); the polarization beam splitter (2) vertically reflects the vertical polarized light in the input light, and the vertical polarized light is deflected 90 degrees in the light propagation direction through a right-angle reflection prism (3), and then converted into horizontal polarized light through a half wave plate (4); the horizontal polarized light output by the delay prism (5) and the horizontal polarized light output by the half wave plate (4) are combined and output through an output plano-convex lens (6).

3. The polarization-independent optical polarization conversion device according to claim 1 is characterized in that the input light is coupled into the polarization beam splitter (2) through an input plano-convex lens (1); the polarization beam splitter (2) transmits the horizontal polarized light in the input light, and the horizontal polarized light is converted into vertical polarized light through a half wave plate (4); the polarization beam splitter (2) vertically reflects the vertical polarized light in the input light, and the vertical polarized light passes through a right-angle reflection prism (3) to complete a 90-degree deflection in the light propagation direction, and then passes through a delay prism (5) for phase compensation; the vertical polarized light output by the delay prism (5) and the vertical polarized light output by the half wave plate (4) are combined and output through an output plano-convex lens (6).

4. The polarization-independent optical polarization conversion device according to claim 2 is characterized in that the input plano-convex lens (1) and the output plano-convex lens (6) are both plano-convex lenses, the input plano-convex lens (1) converts the input light located at the left focus of the lens into parallel light and transmits it in the polarization beam splitter (2), the right-angle reflection prism (3), the half-wave plate (4) and the delay prism (5), and the output plano-convex lens (6) couples the parallel light transmitted to the lens to the output located at the right focus of the lens.

5. The polarization-independent optical polarization conversion device according to claim 1, characterized in that the polarization beam splitter (2) transmits incident horizontally polarized light and reflects incident vertically polarized light.

6. The polarization-independent optical polarization conversion device according to claim 1 is characterized in that the angle between the optical axis direction of the half wave plate (4) and the polarization direction of the incident linear polarized light is 45 degrees, so that the polarization direction of the incident linear polarized light rotates 90 degrees after passing through the half wave plate (4).

7. The polarization-independent optical polarization conversion device according to claim 1 is characterized in that the transmission phase of the input light transmitted to the right focus of the output plano-convex lens (6) through the polarization beam splitter (2), the delay prism (5) and the output plano-convex lens (6) is The input light passes through the polarization beam splitter (2), the right-angle reflection prism (3), the half-wave plate (4) and the output plano-convex lens (6), and the transmission phase of the light transmitted to the right focus of the output plano-convex lens (6) is: The delay prism (5) completes the phase difference compensation between the above two optical paths, so that 8. An optical chip integrated structure, characterized in that: include: An optical chip (9) and an optical polarization conversion device, wherein the optical polarization conversion device is a polarization-independent optical polarization conversion device as claimed in any one of claims 1 to 7, and an optical signal is interconnected between the optical polarization conversion device and the optical chip (9).

9. The optical chip integrated structure according to claim 8, characterized in that: The optical polarization conversion device and the optical chip (9) are interconnected by optical signals via a first output optical fiber (72); Preferably, the optical polarization conversion device is packaged by a first tube shell (81), the optical chip (9) is packaged by a second tube shell (82), one end of the first output optical fiber (72) is located at the optical signal output end of the optical polarization conversion device and is packaged together with the optical polarization conversion device in the first tube shell (81), and the other end of the first output optical fiber (72) is located at the optical signal input end of the optical chip (9) and is packaged together with the optical chip (9) in the second tube shell (82); Preferably, it also includes an input optical fiber (71) connected to the optical polarization conversion device to input light to the optical polarization conversion device, and a second output optical fiber (73) connected to the optical chip (9) to output light; Preferably, the input optical fiber (71) is located at the optical signal input end of the optical polarization conversion device and is packaged together with the optical polarization conversion device in a first tube shell (81), and the second output optical fiber (73) is located at the optical signal output end of the optical chip (9) and is packaged together with the optical chip (9) in a second tube shell (82); Preferably, the input optical fiber (71) is an ordinary single-mode optical fiber, the first output optical fiber (72) is a polarization-maintaining optical fiber, and the second output optical fiber (73) is an ordinary single-mode optical fiber or a polarization-maintaining optical fiber; and the optical chip (9) is a single-polarization input and output optical chip.

10. The optical chip integrated structure according to claim 8, characterized in that: The optical polarization conversion device and the optical chip (9) are co-packaged via a third tube shell (83), and the input end face of the optical chip (9) is located at the right focus of the output plano-convex lens (6).

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