Laser transmitter

Abstract

The invention discloses a laser transmitter, and the transmitter comprises a housing which is provided with an accommodation cavity; the laser emitting module is arranged in the accommodating cavity and is used for emitting laser; the external modulation module is arranged in the accommodating cavity and is used for receiving and modulating the laser emitted by the laser emission module; the optical coupling module is arranged between the laser emission module and the external modulation module and is configured to realize coupling between the laser emission module and the external modulation module; the emitter further comprises a shielding unit, the shielding unit comprises a metal partition, the metal partition is provided with an optical window, and the optical window is arranged between the laser emitting module and the external modulation module and used for communication of an optical path between the laser emitting module and the external modulation module. An electromagnetic shielding layer is arranged on the surface of the metal partition to shield crosstalk between the laser emission module and the external modulation module. According to the invention, crosstalk between the laser emission module and the external modulation module can be avoided, and the performance of the laser emitter is improved.

Description

Technical Field

[0001] The present application relates to the field of hybrid integrated microwave photonics, and in particular to a laser transmitter. Background Art

[0002] In the prior art, the modulation bandwidth of the existing laser transmitter cannot meet the use requirements of high-bandwidth devices, and in the existing lens coupling structure design, the driving circuit of the laser and the driving circuit of the external modulator affect each other, causing crosstalk between them. Moreover, this crosstalk problem is particularly serious in high-bandwidth devices, and technological innovation is urgently needed to make a breakthrough. Summary of the invention

[0003] In order to solve the deficiencies of the prior art, this application adopts the following technical solutions:

[0004] The present application provides a laser transmitter, the transmitter comprising:

[0005] A housing is formed with a receiving cavity;

[0006] A laser emitting module, disposed in the accommodating cavity and used for emitting laser;

[0007] An external modulation module, disposed in the accommodating cavity, for receiving and modulating the laser emitted by the laser emitting module;

[0008] An optical coupling module, disposed between the laser emitting module and the external modulation module, and configured to achieve coupling between the laser emitting module and the external modulation module;

[0009] The transmitter also includes a shielding unit, which includes a metal partition. The metal partition is provided with an optical window. The optical window is arranged between the laser emission module and the external modulation module for connecting the optical path between the laser emission module and the external modulation module. In addition, an electromagnetic shielding layer is provided on the surface of the metal partition to shield the crosstalk between the laser emission module and the external modulation module.

[0010] In summary, the present application provides a laser transmitter, which sets a shielding unit between the laser transmitter module and the external modulation module, thereby separating the laser transmitter module and the external modulation module in two chambers through a metal partition without affecting the penetration of the optical path; and sets an electromagnetic shielding layer on the metal partition to isolate the interference signal in the laser transmitter, avoid crosstalk between the laser transmitter module and the external modulation module, and improve the performance of the laser transmitter.

[0011] Furthermore, the shielding unit also includes a plane lens, and the plane lens is arranged on the optical window.

[0012] Furthermore, the light transmittance of the plane lens is greater than 0.9.

[0013] Furthermore, the optical coupling module includes a collimating lens, an isolator and a converging lens arranged along the optical path, and the laser emitted by the laser emitting module enters the external modulation module after passing through the collimating lens, the isolator and the converging lens;

[0014] Wherein, the optical window is arranged between the isolator and the collimating lens.

[0015] Furthermore, the optical coupling module includes a collimating lens, an isolator and a converging lens arranged along the optical path, and the laser emitted by the laser emitting module enters the external modulation module after passing through the collimating lens, the isolator and the converging lens;

[0016] Wherein, the optical window is arranged between the isolator and the converging lens.

[0017] Furthermore, the distance from the collimating lens to the isolator is smaller than the distance from the converging lens to the isolator, and the distance from the optical window to the isolator is smaller than the distance from the optical window to the converging lens.

[0018] Furthermore, the area of ​​the optical window is substantially equal to the area of ​​the collimating lens and / or the converging lens.

[0019] Furthermore, the external modulation module includes an external modulator and an external modulator driving circuit, and the bandwidth of the external modulator is greater than or equal to 40 GHz.

[0020] Furthermore, the external modulator adopts a thin film lithium niobate modulator.

[0021] Furthermore, the laser emission module adopts a narrow linewidth laser chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of a laser transmitter provided in one embodiment of the present application;

[0023] Figure 2 A schematic diagram of an optical window in a laser transmitter provided in one embodiment of the present application;

[0024] Figure 3 A schematic diagram of a laser transmitter provided in another embodiment of the present application, in which a plane lens is arranged at the optical window position;

[0025] Figure 4 This is a schematic diagram of the spectrum of a laser transmitter light source without a flat lens in the present application;

[0026] Figure 5A schematic diagram of a spectrum of a laser transmitter light source with an additional flat lens provided in another embodiment of the present application;

[0027] Figure 6 A schematic diagram of the position of a shielding unit in a laser transmitter provided in an embodiment of the present application;

[0028] Figure 7 A schematic diagram of the device position relationship of a laser transmitter optical coupling module provided in the present application without an optical window;

[0029] Figure 8 For this application Figure 7 The simulation result diagram of the laser transmitter without optical window is provided;

[0030] Fig. 9 A schematic diagram of the device position relationship of a laser transmitter optical coupling module provided in an embodiment of the present application;

[0031] Fig.10 For this application Fig. 9 A simulation result diagram of a laser transmitter with a device position of an optical coupling module is provided;

[0032] Fig.11 A schematic diagram of the positional relationship between a laser transmitter optical coupling module and a shielding unit provided in one embodiment of the present application;

[0033] Fig.12 For this application Fig.11 A simulation result diagram of a laser transmitter with an additional shielding unit is provided;

[0034] Fig.13 A schematic diagram of the positional relationship between a laser transmitter optical coupling module and a shielding unit provided in another embodiment of the present application; DETAILED DESCRIPTION

[0035] The present application will be described in detail below in conjunction with the specific implementation modes shown in the accompanying drawings, but these implementation modes do not limit the present application. Structural, methodological, or functional changes made by ordinary technicians in the field based on these implementation modes are included in the protection scope of the present application.

[0036] In order to solve the deficiencies of the prior art, the present application provides a laser transmitter, comprising:

[0037] A housing is formed with a receiving cavity;

[0038] A laser emission module is disposed in the accommodating cavity and is used to emit laser;

[0039] The external modulation module is arranged in the accommodating cavity and is used to receive and modulate the laser emitted by the laser emitting module 12;

[0040] An optical coupling module is disposed between the laser emitting module and the external modulation module and is configured to achieve coupling between the laser emitting module and the external modulation module;

[0041] The transmitter also includes a shielding unit, which includes a metal partition. The metal partition is provided with an optical window. The optical window is arranged between the laser emission module and the external modulation module for connecting the optical path between the laser emission module and the external modulation module. In addition, an electromagnetic shielding layer is arranged on the surface of the metal partition to shield the crosstalk between the laser emission module and the external modulation module.

[0042] Specifically, Figure 1 As shown, in the laser transmitter provided in this embodiment, the housing 11 is formed with a accommodating cavity for arranging the laser emission module 12 and the external modulation module 13 of the laser transmitter. The laser emission module 12 may include a laser chip and a laser driving circuit, and the laser driving circuit is used to drive the laser chip to emit laser. The external modulation module 13 may include an external modulator and an external modulator driving circuit, and the external modulator driving circuit is used to drive the external modulator to receive the laser emitted by the laser emission module 12, and the external modulator modulates the received laser and outputs the modulated laser through an optical fiber. The optical coupling module 14 is arranged between the above-mentioned laser emission module 12 and the external modulation module 13, and the laser emission module 12 is coupled to the external modulation module 13 through the optical coupling module 14, and the external modulation module 13 receives the laser emitted by the laser emission module 12 through the optical coupling module 14.

[0043] like Figure 1 As shown, the laser transmitter is provided with a shielding unit 15, which is provided between the laser emitting module 12 and the external modulation module 13. The shielding unit 15 includes a metal partition 152, and an optical window 151 is provided on the metal partition 152. Figure 1 As shown, the laser emitted by the laser emitting module 12 is irradiated to the external modulation module 13 through the optical coupling module 14 and the optical window 151 on the metal partition 152, thereby separating the laser emitting module 12 and the external modulation module 13 in two chambers without affecting the optical path; at the same time, an electromagnetic shielding layer is set on the surface of the metal partition 152 to avoid crosstalk between the laser emitting module 12 and the external modulation module 13.

[0044] Furthermore, the electromagnetic shielding layer may be made of rubber-based microwave absorbing material.

[0045] In one embodiment, if Figure 2 As shown, the optical window 151 is a hollow window.

[0046] Optionally, in another embodiment, as Figure 3As shown, a plane lens 153 may be disposed at the position of the optical window 151 to ensure the laser transmission efficiency while increasing the radio frequency isolation.

[0047] When the plane lens is not provided 153, as Figure 4 As shown, the noise of the laser transmitter at 500k is high. After adding the plane lens 153, as shown in FIG. Figure 5 As shown, the noise of the laser transmitter at 500k is significantly suppressed, thereby improving the performance of the laser transmitter.

[0048] Further, as an optional implementation, the light transmittance of the above-mentioned plane lens 153 is greater than 0.9, thereby reducing the loss of the optical path.

[0049] As an optional implementation method, in the laser transmitter provided in this embodiment, the optical coupling module 14 includes a collimating lens 141, an isolator 142 and a converging lens 143 arranged along the optical path, and the laser emitted by the laser transmitting module 12 passes through the collimating lens 141, the isolator 142 and the converging lens 143 in sequence and then enters the external modulation module 13; wherein, the optical window 151 is arranged between the isolator 142 and the converging lens 143.

[0050] Further, as an optional implementation, in the above-mentioned laser transmitter, the distance from the collimating lens 141 to the isolator 142 is smaller than the distance from the converging lens 143 to the isolator 142, and the distance from the optical window 151 to the isolator 142 is smaller than the distance from the optical window 151 to the converging lens 143.

[0051] Specifically, Figure 1 and Figure 6 As shown, the shielding unit 15 is disposed between the isolator 142 and the converging lens 143 of the optical coupling module 14, and the optical window 151 is located between the isolator 142 and the converging lens 143. The laser emitted by the laser emitting module 12 first passes through the collimating lens 141 and the isolator 142 of the optical coupling module 14 in sequence, then passes through the optical window 151, passes through the converging lens 143 after passing through the optical window 151, and finally enters the external modulation module 13.

[0052] Furthermore, the collimating lens 141, the isolator 142 and the converging lens 143 of the optical coupling module 14 are separated from the metal partition 152 and are located on both sides of the optical window 152 on the metal partition 152, so that the collimating lens 141 and the converging lens 143 can be adjusted according to the coupling efficiency and the size of the light spot, which is convenient for shaping and tuning of the light.

[0053] like Figure 7 As shown, the optical window 151 is not provided in the laser transmitter. Figure 7The distances between the components of the optical coupling module 14 are shown in Table 1, where L1 represents the distance between the collimating lens 141 and the laser chip, L2 represents the distance between the collimating lens 141 and the isolator 142, L3 represents the distance between the isolator 142 and the converging lens 143, and L4 represents the distance between the converging lens 143 and the external modulator. Figure 8 As shown, the simulation result of the coupling efficiency is 0.974 at this time.

[0054] The distance between the components in the simulation Unit: mm L1 0.3 L2 0.2 L3 0.2 L4 0.356

[0055] Table 1

[0056] like Fig. 9 As shown, in a laser transmitter provided in an embodiment, the length of the distance L3 between the isolator 142 and the converging lens 143 is increased to provide space for the setting of the optical window 151. At this time, the distances between the components of the optical coupling module 14 are as shown in Table 2. Fig.10 As shown, the simulation result of the coupling efficiency is 0.973 at this time.

[0057] The distance between the components in the simulation Unit: mm L1 0.3 L2 0.2 L3 0.9 L4 0.356

[0058] Table 2

[0059] According to the above description, Figure 8 and Fig.10 From the comparison of the simulated coupling efficiency, it can be seen that since the optical path between the collimating lens 141 and the converging lens 143 is collimated, the change in the length of the distance L3 between the isolator 142 and the converging lens 143 has little effect on the coupling efficiency. It is feasible to extend the distance L3 between the isolator 142 and the converging lens 143 to provide space for the setting of the optical window 151.

[0060] Furthermore, if Fig.11 As shown, in the laser transmitter provided by another embodiment, an optical window 151 is provided between the isolator 142 and the converging lens 143. The distances between the components are shown in Table 3, wherein L1 represents the distance between the collimating lens 141 and the laser chip, L2 represents the distance between the collimating lens 141 and the isolator 142, L3 represents the distance between the isolator 142 and the optical window 151, L4 represents the distance between the optical window 151 and the converging lens 143, and L5 represents the distance between the converging lens 143 and the external modulator.

[0061] The distance between the components in the simulation Unit: mm L1 0.3 L2 0.2 L3 0.5 L4 2 L5 0.356

[0062] Table 3

[0063] It can be seen from Table 3 that the sum of the distance L3 between the isolator 142 and the optical window 151 and the distance L4 between the optical window 151 and the converging lens 143 is greater than the distance L2 between the collimating lens 141 and the isolator 142, and the distance L3 between the isolator 142 and the optical window 151 is less than the distance L4 between the optical window 151 and the converging lens 143. Fig.12 As shown, after adding the optical window 151, the simulation result of the coupling efficiency is 0.935.

[0064] According to the above description, Fig.10 and Fig.12 From the comparison of the simulated coupling efficiency, it can be seen that after adding the optical window 151, the coupling efficiency of the laser emitter still reaches above 0.9, which meets the coupling efficiency condition of the laser emitter. In addition, by setting the optical window 151 on the metal partition 152, the electromagnetic shielding layer on the metal partition 152 can isolate the interference signal in the laser emitter, thereby improving the performance of the laser emitter.

[0065] As another optional implementation, in the laser transmitter provided in this embodiment, the optical coupling module 14 includes a collimating lens 141, an isolator 142 and a converging lens 143 arranged along the optical path, and the laser emitted by the laser transmitting module 12 enters the external modulation module 13 after passing through the collimating lens 141, the isolator 142 and the converging lens 143; wherein the optical window 151 is arranged between the isolator 142 and the collimating lens 141.

[0066] Specifically, Figure 1 and Fig.13 As shown, the shielding unit 15 is disposed between the collimating lens 141 and the isolator 142 of the optical coupling module 14, and the optical window 151 is located between the collimating lens 141 and the isolator 142. The laser emitted by the laser emitting module 12 first passes through the collimating lens 141 of the optical coupling module 14, then passes through the optical window 151 and the isolator 142 in sequence, then passes through the converging lens 143, and finally enters the external modulation module 13.

[0067] Furthermore, as an optional implementation method, the area of ​​the above-mentioned optical window 151 is not less than the area of ​​the collimating lens 141 and / or the converging lens 143, so as to ensure the transmission efficiency of the laser; and the area of ​​the optical window 151 is approximately substantially equal to the area of ​​the collimating lens 141 and / or the converging lens 143, thereby avoiding the size of the optical window 151 from affecting the electromagnetic shielding layer on the metal partition 152 and increasing the RF isolation.

[0068] As an optional implementation, in the laser transmitter provided in this embodiment, the external modulation module 13 includes an external modulator and an external modulator driving circuit, the external modulator driving circuit drives the external modulator to receive the laser, and the external modulator modulates the laser and then emits the light through the optical fiber. As an optional implementation, in the laser transmitter provided in this embodiment, the external modulator adopts a thin-film lithium niobate modulator to improve the performance of the external modulation module 13. Furthermore, in the laser transmitter provided in this embodiment, by adopting a thin-film lithium niobate modulator, the bandwidth of the laser transmitter is increased to greater than or equal to 40 GHz.

[0069] As an optional implementation, in the laser transmitter provided in this embodiment, the laser transmitting module 12 adopts a narrow line width laser chip to improve the performance of the laser transmitting module 12 .

[0070] According to the above description, the present application implements a laser transmitter, which sets a shielding unit 15 between the laser transmitter module 12 and the external modulation module 13, so that the laser transmitter module 12 and the external modulation module 13 are separated and set in two chambers through a metal partition 152 without affecting the penetration of the optical path; and an electromagnetic shielding layer is set on the metal partition 152 to isolate the interference signal in the laser transmitter, avoid crosstalk between the laser transmitter module 12 and the external modulation module 13, and improve the performance of the laser transmitter; and by adopting a thin film lithium niobate modulator, the bandwidth of the laser transmitter is increased to greater than or equal to 40GHz, thereby further improving the performance of the laser transmitter.

[0071] It will be appreciated that the word "exemplary" as used herein means "serving as an example, instance, or illustration". Any embodiment described as "exemplary" is not necessarily preferred or superior to other embodiments and / or does not exclude the combination of features of other embodiments. It will be appreciated that certain features of the present application described in the context of separate embodiments for the sake of clarity may also be provided in a single embodiment by combination. Conversely, various features of the present application described in the context of a single embodiment for the sake of clarity may also be provided individually or in any suitable combination or as any other described embodiment of the present application.

[0072] The above disclosure is only the preferred embodiment of the present application, but it is not intended to limit the scope of rights of the present application. A person of ordinary skill in the art can understand that without departing from the spirit and scope of the present application and the appended claims, changes, modifications, substitutions, combinations, and simplifications should all be equivalent replacement methods and still fall within the scope of the invention.

[0073] The application fields of the technology of the present invention include but are not limited to pipeline safety. As long as the essence of the technical solution does not deviate from the scope of the technical solution of each embodiment of the present invention, it falls within the protection scope of the present invention.

Claims

1. A laser transmitter, comprising: A housing is formed with a receiving cavity; A laser emitting module, disposed in the accommodating cavity and used for emitting laser; An external modulation module, disposed in the accommodating cavity, for receiving and modulating the laser emitted by the laser emitting module; An optical coupling module, disposed between the laser emitting module and the external modulation module, and configured to achieve coupling between the laser emitting module and the external modulation module; It is characterized in that the transmitter also includes a shielding unit, which includes a metal partition. The metal partition is provided with an optical window, and the optical window is arranged between the laser emission module and the external modulation module for connecting the optical path between the laser emission module and the external modulation module. In addition, an electromagnetic shielding layer is provided on the surface of the metal partition to shield the crosstalk between the laser emission module and the external modulation module.

2. The laser transmitter according to claim 1, characterized in that: The shielding unit further includes a plane lens, and the plane lens is arranged on the optical window.

3. The laser transmitter according to claim 2, characterized in that: The light transmittance of the plane lens is greater than 0.

9.

4. The laser transmitter according to claim 2, characterized in that: The optical coupling module includes a collimating lens, an isolator and a converging lens arranged along the optical path, and the laser emitted by the laser emitting module enters the external modulation module after passing through the collimating lens, the isolator and the converging lens; Wherein, the optical window is arranged between the isolator and the collimating lens.

5. The laser transmitter according to claim 2, characterized in that: The optical coupling module includes a collimating lens, an isolator and a converging lens arranged along the optical path, and the laser emitted by the laser emitting module enters the external modulation module after passing through the collimating lens, the isolator and the converging lens; Wherein, the optical window is arranged between the isolator and the converging lens.

6. The laser transmitter according to claim 5, characterized in that: The distance from the collimating lens to the isolator is shorter than the distance from the converging lens to the isolator, and the distance from the optical window to the isolator is shorter than the distance from the optical window to the converging lens.

7. The laser transmitter according to claim 4 or 5, characterized in that: The area of ​​the optical window is substantially equal to the area of ​​the collimating lens and / or the converging lens.

8. The laser transmitter according to claim 1, characterized in that: The external modulation module includes an external modulator and an external modulator driving circuit, and the bandwidth of the external modulator is greater than or equal to 40 GHz.

9. The laser transmitter according to claim 8, characterized in that: The external modulator uses a thin film lithium niobate modulator.

10. The laser transmitter according to claim 1, characterized in that: The laser emission module adopts a narrow line width laser chip.

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