Optical path module and space laser communication device

Abstract

The embodiment of the present application provides an optical path module and a space laser communication device, wherein the optical path module comprises a first dichroic mirror configured to reflect first wavelength light and transmit second wavelength light; a second dichroic mirror configured to transmit the first wavelength light and reflect the second wavelength light; a first fast control mirror configured to reflect the first wavelength light; and a second fast control mirror configured to reflect the second wavelength light; wherein the first dichroic mirror, the first fast control mirror and the second dichroic mirror form a first optical path of the first wavelength light from a first port to a second port; and the first dichroic mirror, the second fast control mirror and the second dichroic mirror form a second optical path of the second wavelength light from the first port to the second port. The embodiment of the present application aims to improve the stability and reliability in the switching of a specific transceiving wavelength state.

Description

Technical Field

[0001] This application relates to the field of space laser communication technology, and in particular to an optical path module and a space laser communication device. Background Technology

[0002] Space laser communication equipment consists of a transmission channel (Tx) and a reception channel (Rx) in its signal path. To ensure isolation between transmission and reception, Tx and Rx use different wavelengths of light. However, this limits a single terminal to a specific transmit and receive wavelength, making communication between two arbitrarily different terminals impossible. Related technologies use motors or other drive mechanisms within the space laser communication equipment to move two dichroic mirrors, switching the optical paths for each wavelength and enabling the equipment to switch between specific transmit and receive wavelengths. However, this method requires extremely high precision from the drive mechanism and calibrates after each switch, resulting in low reliability and failing to meet the reliability requirements of spaceborne scenarios. Improving the reliability and stability of the equipment while maintaining compatibility with different transmit and receive wavelengths is a pressing issue that needs to be discussed and resolved. Summary of the Invention

[0003] This application provides an optical path module and a space laser communication device, which aims to improve the reliability and stability of the device while being compatible with different transmit and receive wavelengths.

[0004] In a first aspect, embodiments of this application provide an optical path module, comprising: a first dichroic mirror for reflecting a first wavelength of light and transmitting a second wavelength of light; a second dichroic mirror for transmitting the first wavelength of light and reflecting the second wavelength of light; a first fast-control mirror for reflecting the first wavelength of light; and a second fast-control mirror for reflecting the second wavelength of light; wherein the first dichroic mirror, the first fast-control mirror, and the second dichroic mirror form a first optical path for the first wavelength of light from a first port to a second port; and the first dichroic mirror, the second fast-control mirror, and the second dichroic mirror form a second optical path for the second wavelength of light from the first port to the second port.

[0005] Secondly, embodiments of this application provide a space laser communication device, including: an optical path module as described in the first aspect; and a photonic module connected to the optical path module.

[0006] In this embodiment, a first dichroic mirror and a second dichroic mirror with different light transmission and reflection effects are simultaneously arranged in the optical path, and two fixed optical paths are formed in conjunction with a first fast control reflector and a second fast control reflector. Specifically, the first dichroic mirror, the first fast control reflector, and the second dichroic mirror form the first optical path for the first wavelength light from the first port to the second port; the first dichroic mirror, the second fast control reflector, and the second dichroic mirror form the second optical path for the second wavelength light from the first port to the second port. The first wavelength light can be transmitted in both receiving and transmitting directions in the fixed first optical path, and the second wavelength light is also transmitted in both receiving and transmitting directions in the fixed second optical path. Therefore, this optical path module can simultaneously accommodate two transmit / receive wavelength states: first wavelength light for receiving and second wavelength light for transmitting, and first wavelength light for receiving and second wavelength light for transmitting. The fixed optical path achieves compatibility between different transmit / receive wavelength states and ensures the reliability and stability of the device.

[0007] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure of an optical path module provided in an embodiment of this application; Figure 2 A schematic diagram of the structure of an optical path module in a transceiver wavelength state according to an embodiment of this application; Figure 3 A schematic diagram of another transceiver wavelength state of the optical path module provided in one embodiment of this application; Figure 4 A schematic diagram of a space laser communication device provided in an embodiment of this application; Figure 5 This is a schematic diagram of a dual-fiber parallel structure provided in an embodiment of this application; Figure 6 A schematic diagram of a transceiver module provided as an example of this application for transmitting a first wavelength of light and receiving a second wavelength of light; Figure 7 A schematic diagram of a transceiver module provided as an example of this application for receiving a signal of a first wavelength light and emitting a second wavelength light; Figure 8 This is a schematic diagram of the structure of a photonic module provided as an example in this application. Detailed Implementation

[0009] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0010] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0011] In the description of the embodiments of this application, unless otherwise expressly limited, terms such as setting, installing, and connecting should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in the embodiments of this application in combination with the specific content of the technical solution.

[0012] In this application, the terms "furthermore," "exemplarily," or "optionally" are used as examples, illustrations, or descriptions and should not be construed as being more preferred or advantageous than other embodiments or designs. The use of terms such as "furthermore," "exemplarily," or "optionally" is intended to present the relevant concepts in a specific manner.

[0013] In related technologies, space laser communication equipment has a signal channel divided into a transmit channel (Tx) and a receive channel (Rx). Tx and Rx signals can use completely independent channels or multiplex a single channel, i.e., separate aperture transceiver and shared aperture transceiver. For spaceborne systems, size and weight are key parameters of concern, and the shared aperture transceiver mechanism is superior to the separate aperture mechanism in terms of size and weight. Therefore, shared aperture transceiver is the common choice for spaceborne systems. Under the shared aperture transceiver mechanism, Tx and Rx use different wavelengths of light to ensure isolation between reception and transmission. However, this limits a single terminal to a specific transmit and receive wavelength, making communication between two arbitrarily different terminals impossible.

[0014] Space laser communication equipment in related technologies uses motors and other drive mechanisms to move dichroic mirrors corresponding to one wavelength λ1 and another wavelength λ2, switching between different optical path structures to achieve specific transmit and receive wavelength states. However, this method requires extremely high precision from the drive mechanism and calibrates after each switch, resulting in low reliability and difficulty meeting the reliability requirements of spaceborne scenarios. It further increases system complexity and cannot guarantee immediate usability after switching. Correspondingly, optical amplifiers and optical modules must also be compatible with dual wavelengths and managed accordingly. This leads to low equipment reliability, making it difficult to meet the reliability requirements of spaceborne scenarios. How to improve equipment reliability and stability while maintaining compatibility with different transmit and receive wavelength states is a problem that urgently needs to be discussed and solved.

[0015] To address the aforementioned issues, this application provides an optical path module and a space laser communication device. By simultaneously incorporating a first dichroic mirror and a second dichroic mirror with different light transmission and reflection effects within the optical path, and cooperating with a first fast control mirror and a second fast control mirror, two fixed optical paths are formed. Specifically, the first dichroic mirror, the first fast control mirror, and the second dichroic mirror form a first optical path for a first wavelength of light from a first port to a second port; the first dichroic mirror, the second fast control mirror, and the second dichroic mirror form a second optical path for a second wavelength of light from a first port to a second port. The first wavelength of light can be transmitted in both receiving and transmitting directions within the fixed first optical path, and the second wavelength of light can also be transmitted in both receiving and transmitting directions within the fixed second optical path. Therefore, this optical path module can simultaneously accommodate both transmit / receive wavelength states: first wavelength light for receiving and second wavelength light for transmitting, and first wavelength light for receiving and second wavelength light for transmitting. This fixed optical path achieves compatibility between different transmit / receive wavelength states and ensures the reliability and stability of the device.

[0016] The embodiments of this application will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the structure of an optical path module provided in one embodiment of this application. Figure 1 As shown, the optical path module includes, but is not limited to, a first dichroic mirror, a second dichroic mirror, a first fast control mirror, and a second fast control mirror.

[0018] The first dichroic mirror is used to reflect light of the first wavelength and transmit light of the second wavelength. The second dichroic mirror is used to transmit light of the first wavelength and reflect light of the second wavelength. The first fast-control mirror is used to reflect light of the first wavelength; The second fast-control mirror is used to reflect the second wavelength of light.

[0019] The first dichroic mirror, the first fast-control mirror, and the second dichroic mirror form a first optical path for light of the first wavelength from the first port to the second port; the first dichroic mirror, the second fast-control mirror, and the second dichroic mirror form a second optical path for light of the second wavelength from the first port to the second port.

[0020] For example, the first and second dichroic mirrors are based on the multilayer thin film interference effect to achieve differentiated processing of high transmission / high reflection for light of a specific wavelength. For example, in this embodiment, the first dichroic mirror is used to reflect the first wavelength light and transmit the second wavelength light, and the second dichroic mirror is used to transmit the first wavelength light and reflect the second wavelength light.

[0021] For example, a fast-steering mirror (FSM) is responsible for reflecting light to control and adjust the light beam. The first fast-steering mirror is an FSM corresponding to the first wavelength of light. As part of the structure of the first optical path, it is responsible for adjusting the first wavelength of light and reflecting it to the target position.

[0022] The second fast reflector is an FSM corresponding to the second wavelength of light. As part of the structure of the second optical path, it is responsible for adjusting the second wavelength of light and reflecting it to the target position.

[0023] It should be noted that the first port and the second port are used to refer to the two ends of the first optical path / second optical path; in the embodiments of this application, the optical path from the first port to the second port refers to the optical path between the first port and the second port, and the first port and the second port are only used to indicate the two ends of the optical path and are not used to define the direction of the optical path. In the various embodiments of this application, the first wavelength light can be transmitted bidirectionally in the first optical path, and the second wavelength light can also be transmitted bidirectionally in the second optical path.

[0024] The transmission paths of the first wavelength light and the second wavelength light in this application under different conditions are explained below with reference to the illustrations.

[0025] For example, Figure 2 This is a schematic diagram of the structure of an optical path module in one embodiment of this application, showing a transmit / receive wavelength configuration. (Refer to...) Figure 2 Assuming the optical path module's transmit and receive wavelength states are in state one, the first wavelength light is used as the transmitted light, and the second wavelength light is used as the received light. For example... Figure 2As shown, when the first wavelength light is used as the emitted light, the first wavelength light is incident from the first port onto the first dichroic mirror. The first dichroic mirror reflects the first wavelength light, and the reflected first wavelength light is incident onto the first fast control mirror. The first fast control mirror reflects the first wavelength light, and the reflected first wavelength light is incident onto the second dichroic mirror. The second dichroic mirror transmits the first wavelength light, and the transmitted first wavelength light is transmitted to the outside of the optical path module through the second port.

[0026] When the second wavelength light is used as the receiving light, the second wavelength light is incident on the second dichroic mirror from the second port; the second dichroic mirror reflects the second wavelength light, and the reflected second wavelength light is incident on the second fast control mirror; the second fast control mirror reflects the second wavelength light, and the reflected second wavelength light is incident on the first dichroic mirror; the first dichroic mirror transmits the second wavelength light, and the transmitted second wavelength light is transmitted to the outside of the optical path module through the first port.

[0027] For example, Figure 3 This is a schematic diagram of another transceiver wavelength state of the optical path module provided in one embodiment of this application.

[0028] Reference Figure 3 Assuming the optical path module's transmit and receive wavelengths are in state two, the first wavelength light is used as the received light, and the second wavelength light is used as the transmitted light. For example... Figure 3 As shown, when the first wavelength light is used as the receiving light, the first wavelength light is incident on the second dichroic mirror from the second port. The second dichroic mirror transmits the first wavelength light, and the transmitted first wavelength light is incident on the first fast control reflector. The first fast control reflector reflects the first wavelength light, and the reflected first wavelength light is incident on the first dichroic mirror. The first dichroic mirror reflects the first wavelength light, and the reflected first wavelength light is transmitted to the outside of the optical path module through the first port.

[0029] When the second wavelength light is used as the emitted light, the second wavelength light is incident from the first port onto the first dichroic mirror; the first dichroic mirror transmits the second wavelength light, and the transmitted second wavelength light is incident onto the second fast-control mirror; the second fast-control mirror reflects the second wavelength light, and the reflected second wavelength light is incident onto the second dichroic mirror, the second dichroic mirror reflects the second wavelength light, and the reflected second wavelength light is transmitted to the outside of the optical path module through the second port.

[0030] In the above example, both the first wavelength light and the second wavelength light can achieve bidirectional transmission. The path of the first optical path can be from the first port to the second port, or from the second port to the first port; similarly, the path of the second optical path can be from the second port to the first port, or from the first port to the second port. The first port and the second port are interchangeable; the first port can act as the transmitting terminal and the second port as the receiving terminal, or the second port can act as the transmitting terminal and the first port as the receiving terminal. Both the first optical path and the second optical path can support bidirectional transmission of the first wavelength light and the second wavelength light.

[0031] For example, the first dichroic mirror, the second dichroic mirror, the first fast control mirror, and the second fast control mirror are all fixedly arranged. When the first wavelength light is used as either emitted or received light, it is transmitted along the formed fixed first optical path. Similarly, when the second wavelength light is used as either emitted or received light, it is transmitted along the formed fixed second optical path. The first and second wavelength lights do not require coaxial calibration after switching transmission and reception directions, and there are no structural changes or alignment mismatches.

[0032] In this embodiment, by simultaneously setting a first dichroic mirror, a second dichroic mirror, a first fast control reflector, and a second fast control reflector in the optical path, wherein the first dichroic mirror, the first fast control reflector, and the second dichroic mirror form a first optical path for the first wavelength light from the first port to the second port, and the first optical path is used as a transmission and reception channel for the first wavelength light; the first dichroic mirror, the second fast control reflector, and the second dichroic mirror form a second optical path for the second wavelength light from the first port to the second port, and the second optical path is used as a transmission and reception channel for the second wavelength light; so that when the emitted light / received light in the photonic module switches between the first wavelength light and the second wavelength light, both the first optical path and the second optical path can perform normal transmission and reception, that is, when the first wavelength light is used as the emitted light / received light in the optical path module, it can share the same optical channel, and similarly, when the second wavelength light is used as the emitted light / received light in the optical path module, it can also share the same optical channel. The first dichroic mirror and the second dichroic mirror can be set in a fixed position in advance. During operation, even when switching between transmit and receive wavelengths, there is no need to further adjust the positions of the first and second dichroic mirrors, nor is it involved in the dynamic adjustment of other related structures, thus achieving highly reliable switching between specific transmit and receive wavelengths.

[0033] In one embodiment, the first optical path formed by the first dichroic mirror, the first fast control mirror, and the second dichroic mirror and the second optical path formed by the first dichroic mirror, the second fast control mirror, and the second dichroic mirror partially overlap.

[0034] like Figure 1As shown, the first dichroic mirror, the first fast control mirror, the second dichroic mirror, and the second fast control mirror work together to form two branched optical paths. The first branched optical path is connected to the first and second dichroic mirrors at both ends, with the first fast control mirror passing through the middle; the second branched optical path is also connected to the first and second dichroic mirrors at both ends, with the second fast control mirror passing through the middle. Except for the portions of the first and second branched optical paths, the first and second optical paths can share a common path.

[0035] In one embodiment, the optical paths of the first wavelength light and the second wavelength light overlap between the first dichroic mirror and the first port; the optical paths of the first wavelength light and the second wavelength light overlap between the second dichroic mirror and the second port.

[0036] For example, still using Figure 2 For example, assuming the optical path module is in state one, the first wavelength light is used as the emitted light. It enters the optical path module from the first port and overlaps with the second optical path before reaching the first dichroic mirror and before reaching the second port from the second dichroic mirror. Similarly, the second wavelength light is used as the received light. It enters the optical path module from the second port and overlaps with the first optical path before reaching the second dichroic mirror and before reaching the first port from the first dichroic mirror. This allows the first wavelength light and the second wavelength light to share part of the optical path regardless of whether they are being transmitted or received, which simplifies the overall optical path structure and reduces the size of the entire optical path module.

[0037] In one embodiment, the optical path module further includes a third fast control mirror, which is located between the second dichroic mirror and the second port.

[0038] In another embodiment, the third fast control mirror may also be located between the first dichroic mirror and the first port.

[0039] The third fast control mirror is a high-speed controllable mirror with the same structure as the first and second fast control mirrors, but its operating wavelength range covers both the first and second wavelengths of light. Located on the common optical path between the dichroic mirror and either the first or second port, the third fast control mirror simultaneously reflects both the first and second wavelengths of light to achieve common-path compensation and directional control of the common-path portion when transmitting and receiving the first and second wavelengths.

[0040] For example, the third fast control mirror is equipped with a fine tracking function. When the first wavelength light or the second wavelength light is used as the emitted light, the light is incident on the third fast control mirror under the action of the second dichroic mirror. When the first wavelength light or the second wavelength light is used as the received light, it enters the optical path module from the second port and enters the third fast control mirror before reaching the second dichroic mirror. In the above process, the third fast control mirror can suppress and correct the micro-disturbances introduced by the first wavelength light and the second wavelength light to the environment, further improving the stability of the transmission of the first wavelength light and the second wavelength light in the optical path module.

[0041] In one embodiment, the optical path module further includes a telescope assembly. Exemplarily, the telescope assembly can be located at either the second port or the first port. When the telescope assembly is located at the second port, the second port serves as an optical transceiver for communication with other space laser communication devices, and the first port serves as an optical transceiver connected to the photonic system. When the telescope assembly is located at the first port, the first port serves as an optical transceiver for communication with other space laser communication devices, and the second port serves as an optical transceiver connected to the photonic system. Taking the telescope assembly located at the second port as an example, the telescope assembly is responsible for beam-shrinking the first wavelength light or the second wavelength light incident on the optical path module from the second port, and the telescope assembly is responsible for collimating and expanding the first wavelength light or the second wavelength light emitted from the second port.

[0042] For example, when the telescope assembly is used as a receiver, it can compress the collected parallel incident light into a small-aperture beam, matching the optical devices at the back end of the optical path module, such as small-sized detectors and fiber optic couplers, to achieve efficient signal reception and coupling. When the telescope assembly is used as a transmitter, it can significantly compress the far-field divergence angle of the beam, reducing energy diffusion during long-distance spatial transmission and allowing the optical signal to be transmitted with higher energy density.

[0043] In one embodiment, both the first fast control mirror and the second fast control mirror are equipped with advance control function and nutation control function.

[0044] The advanced control function refers to rapidly controlling the reflector to generate a small angular deflection in advance according to a preset algorithm or external command, in order to compensate for aiming point deviations caused by optical aberration or relative target motion during long-distance spatial transmission of the optical signal. The nutation control function refers to rapidly controlling the reflector to perform high-speed, small-amplitude circular or helical scanning motion within a small angular range, in order to optimize the efficiency of coupling the received light into the single-mode fiber, achieving active coupling control similar to jitter or scanning.

[0045] For example, suppose a space laser communication device equipped with the optical path module of this application communicates with satellite device A and satellite device B respectively. When communicating with satellite device A, the device uses a first wavelength light as the transmitted light and a second wavelength light as the received light. The device instructs the first fast control mirror to enable the advance control function to adjust the advance pointing of the first wavelength light according to ephemeris data through the control software; at the same time, it instructs the second fast control mirror to enable the nutation control function to perform high-speed nutation to ensure that the second wavelength light is efficiently coupled into the optical fiber. When communicating with satellite device B, the device switches its transmit and receive wavelength states. At this time, the first wavelength light is used as the received light and the second wavelength light is used as the transmitted light. At this time, the first and second fast control mirrors switch functions. The control software instructs the first fast control mirror to stop the advance function and start performing nutation scanning, while the second fast control mirror stops nutation and starts performing advance pointing adjustment according to the new ephemeris data.

[0046] In the above embodiments, by simultaneously configuring both advance control and nutation control functions for the first and second fast control mirrors, the functions of the first and second fast control mirrors can be dynamically interchanged according to the current transmit and receive wavelength state. This not only enhances the wavelength switching capability of the optical path module, but also enables the optical path module to still have high-performance tracking and aiming capabilities after the wavelength state is switched, thereby improving the flexibility and intelligence of the optical path module.

[0047] In one embodiment, a collimator is disposed between the first dichroic mirror and the first port. The collimator is a passive optical device that converts a diverging beam in an optical fiber into collimated light (parallel light), or couples parallel light back into the optical fiber.

[0048] For example, the first optical path and the second optical path share a collimator. When the first wavelength light or the second wavelength light is used as the emitted light, the first wavelength light or the second wavelength light is in a divergent state. After the first wavelength light or the second wavelength light passes through the collimator, the collimator can shape the first wavelength light or the second wavelength light into a parallel collimated beam with a very small emission angle and emit it to the first dichroic mirror, which greatly reduces the coupling loss of the first wavelength light or the second wavelength light in the subsequent transmission in the optical path.

[0049] When the first wavelength light or the second wavelength light is used as the receiving light, after the first wavelength light or the second wavelength light is incident on the collimator through the first dichroic mirror, the collimator can accurately focus the first wavelength light or the second wavelength light and then send it into the optical receiver (such as the optical receiver of the photonic module), so as to achieve efficient coupling with the optical receiver, ensure the accuracy of reading the first wavelength light or the second wavelength light, and maximize the coupling efficiency.

[0050] In the above embodiments, the first and second optical paths share a collimator, which reduces the difficulty of converting waveguide light to spatial light and the bidirectional transmission loss in the optical path. This improves the efficiency of optical signals in bidirectional transmission, simplifies the optical path structure, reduces the number of devices used, and helps to reduce the overall size of the optical path module.

[0051] Figure 4 This is a schematic diagram of a space laser communication device provided in one embodiment of this application. Figure 4 As shown, the space laser communication device includes, but is not limited to, the optical path module and the photonic module provided in the above embodiments, with the photonic module connected to the optical path module.

[0052] For example, the photonic module is connected to the optical path module through a first port. The photonic module can generate a first wavelength light or a second wavelength light as emitted light. The first wavelength light or the second wavelength light enters the optical path module through the first port. The photonic module can perform operations on the first wavelength light or the second wavelength light, including but not limited to encoding, modulation, and amplification. For example, it can adjust the emitted light based on the different wavelengths of the first wavelength light and the second wavelength light to meet wavelength requirements. The photonic module can also receive the first wavelength light or the second wavelength light as received light. The first wavelength light or the second wavelength light is incident on the photonic module through the first port. The photonic module performs operations on the first wavelength light or the second wavelength light as received light, including but not limited to mixing, detection, and decoding, thereby obtaining the information carried by the first wavelength light or the second wavelength light.

[0053] In one embodiment, the photonic module is connected to the optical path module via a dual-fiber parallel connection through an optical coupling interface. Here, dual-fiber parallel connection refers to a coating layer containing two optical fibers, one for transmitting transmitted light and the other for transmitting received light.

[0054] For example, the photonic module and the optical path module are connected via parallel fiber coupling, enabling bidirectional transmission of both a first wavelength and a second wavelength of light simultaneously at a single port. For instance, one fiber may be used to transmit the first wavelength light, and the other to receive the second wavelength light; or one fiber may be used to transmit the second wavelength light, and the other to receive the first wavelength light. The two fibers are independent optical transmission channels, and the two fibers are optically isolated and do not interfere with each other.

[0055] For example, Figure 5This is a schematic diagram of a dual-fiber parallel structure provided in an embodiment of this application. To ensure the accuracy of reception when the first wavelength light / second wavelength light is used as the receiving light, the fiber used for receiving in the dual-fiber parallel structure (assuming fiber core 1 corresponds to the transmitting fiber) is aligned with the optical axis of the collimator in the aforementioned embodiment. The resulting angular error caused by the eccentricity of the axis of the transmitting fiber (fiber core 2) relative to the collimator can be compensated for by zero-position preset using the advance control function of the reflector. The compensation angle is determined by... Figure 5 The distance d between fiber core 1 and fiber core 2 shown is determined by the focal length of the end-to-end transmission system. The focal length of the end-to-end transmission system refers to the focal length of the entire transmission optical path with the collimator and telescope assembly at both ends.

[0056] In one embodiment, the photonic module includes a tunable laser source for generating light of a first wavelength or a second wavelength. The tunable laser source is a laser capable of continuously or incrementally changing its output wavelength within a certain wavelength range. Its function is to enable the photonic module to generate at least two specific wavelength optical signals as needed, thereby matching the wavelength state switching of the optical path module.

[0057] For example, a tunable laser source can dynamically adjust its own resonant cavity parameters, such as changing the grating period, adjusting the operating temperature, or adjusting the resonant cavity length, thereby generating a first wavelength light or a second wavelength light.

[0058] For example, the photonic module in a space laser communication device includes a tunable laser with a wavelength covering the entire communication band. When the device needs to emit light at a first wavelength and receive light at a second wavelength, the tunable laser is set to output light at the first wavelength; when it needs to switch to emitting light at the second wavelength and receiving light at the first wavelength, the controller sends a command to the tunable laser to change the output wavelength to the second wavelength.

[0059] In one embodiment, the photonic module includes an optical amplifier for amplifying either a first wavelength or a second wavelength of light. The optical amplifier is an active optical device that can directly enhance the power of an optical signal without converting it into an electrical signal. Exemplarily, the optical amplifier is a dual-wavelength gain-flat type, capable of amplifying either the first or second wavelength of light. By incorporating an optical amplifier capable of simultaneously amplifying both wavelengths within the photonic module, and because the optical amplifier eliminates the need for a wavelength switching mechanism and provides consistent gain performance for both wavelengths, the wavelength gain capability of the optical amplifier, combined with the wavelength switching capability of the tunable laser source and the optical path module, ensures that the optical amplifier provides effective power gain support regardless of the wavelength state of the space laser communication device. This ensures that the power of the communication link remains stable before and after wavelength switching, thereby guaranteeing consistent communication quality.

[0060] In some embodiments, the space laser communication equipment also includes detectors for tracking and aiming detection. These detectors include, but are not limited to, charge-coupled devices (CCDs), complementary metal-oxide-semiconductor (CMOS) detectors, quadrant detectors (QDs), and indium gallium arsenide (InGaAs) array detectors. While these detectors are part of the space laser communication equipment, they are not part of the core structure of the optical path module compatible with different wavelengths of light provided in the embodiments of this application. Therefore, the detectors are within the protection scope of this application regardless of their location within the optical path module.

[0061] In some embodiments, the optical axis calibration module with the pyramid as the core component does not involve the core structure of the optical path module that is compatible with the transmission and reception of different wavelengths of light provided in the various embodiments of this application. Therefore, the pyramid is located at any position in the optical path module and is within the protection scope of this patent.

[0062] The optical path module of this application will be described in general detail below through several examples. It should be understood that the following embodiments are for the purpose of better illustrating the optical path module of this application and are not intended to be specific or limiting.

[0063] Example 1: For example, a space laser communication device can consist of two parts: an optical path module and a photonic module. The optical path module is a passive transceiver channel used to collimate and expand the light beam, receive and shrink the beam, and adjust and detect the beam. The photonic module is used to realize functions such as laser signal generation, reception, modulation, encoding and decoding, and amplification.

[0064] Figure 6 This is a schematic diagram illustrating the signal transmission and reception of an optical path module providing an example of this application, showing the transmission of a first wavelength of light and the reception of a second wavelength of light. (Refer to...) Figure 6 The dashed box in the diagram corresponds to the optical path module. For example... Figure 6 As shown, assume that the first wavelength light is the emitted light, i.e., Tx: λ1, and the second wavelength light is the received light, i.e., Rx: λ2.

[0065] The optical path module includes: a. Dichroic Mirror (DM): This mirror separates the transmit channel Tx and the receive channel Rx by wavelength, achieving transmit-receive separation. As shown in the figure, the dichroic mirror DM includes a first dichroic mirror DM_A and a second dichroic mirror DM_B.

[0066] b. Fast Steering Mirror (FSM): This includes the Precision Fast Steering Mirror (FSM), the Leading Fast Steering Mirror (FSM), and the Nudging Fast Steering Mirror (FSM), among which: (1) The precision tracking and fast control mirror is set in the common optical path of the transmitter and receiver to suppress micro-disturbances introduced by the environment; (2) An advanced fast control reflector is set in the transmitting optical path to compensate for the time delay introduced by the spatial channel transmission; (3) A nutation fast control reflector is set in the receiving optical path to accurately compensate the received light entering the single-mode fiber on the receiving side.

[0067] c. Telescope system: used to expand and collimate the transmitted beam and to reduce the received beam; d. Collimator: Includes a collimator. The collimator in the transmitting optical path is used for primary collimation of the laser emitted by the photonic module, and the collimator in the receiving optical path is used to converge the beam of the telescope system into the receiving side single-mode fiber.

[0068] For example, combined Figure 6 The signal transmission process of the space laser communication device in this example is as follows: The photonic module emits a first wavelength light with wavelength λ1 to the optical path module. After being collimated by the collimator, the first wavelength light is reflected at DM_A (first dichroic mirror) (λ1@R, where R is Reflectivity). The first wavelength light with wavelength λ1 is incident on the leading FSM (first fast control mirror) at this time. After being reflected by the leading FSM, it reaches DM_B (second dichroic mirror). The first wavelength light with wavelength λ1 is transmitted at DM_B (λ1@T, where T is Transmissivity). After DM_B, the first wavelength light with wavelength λ1 enters the common optical path of Tx and Rx. After being reflected by the fine-tracking FSM (third control mirror) and collimated and expanded by the telescope system, it is emitted to the space channel.

[0069] For example, combined Figure 6The signal reception process of the space laser communication device in this example is as follows: A second wavelength light with wavelength λ2 from the space channel enters the telescope system and is beam-constricted by the telescope system. The beam-constricted second wavelength light with wavelength λ2 is reflected by the fine-tuning FSM. The second wavelength light with wavelength λ2 after being reflected by the fine-tuning FSM reaches DM_B. DM_B reflects the second wavelength light with wavelength λ2 (λ2@R). The second wavelength light with wavelength λ2 after being reflected by DM_B is incident on the nutating FSM (second fast-control mirror) and reflected by the nutating FSM to DM_A. DM_A transmits the second wavelength light with wavelength λ2 (λ2@T). The second wavelength light with wavelength λ2 transmitted through DM_A is received by the photonic module.

[0070] Example 2: Figure 7 This is a schematic diagram illustrating the signal transceiver function of an optical path module provided in Example 1 of this application, which receives light of a first wavelength and emits light of a second wavelength. This example uses the space laser communication device and optical path module provided in Example 1.

[0071] In this example, such as Figure 7 As shown, assume that the second wavelength light is the emitted light, i.e., Tx: λ2, and the first wavelength light is the received light, i.e., Rx: λ1.

[0072] For example, combined Figure 7 The signal transmission process of the space laser communication device in this example is as follows: The photonic module transmits a second wavelength light with wavelength λ2 to the optical path module. After the first wavelength light is collimated by the collimator, it is transmitted at DM_A (first dichroic mirror) (λ2@T). The transmitted light is incident on the leading FSM (second fast control mirror) at this time. After being reflected by the leading FSM, it reaches DM_B (second dichroic mirror). The second wavelength light with wavelength λ2 is reflected at DM_B (λ2@R). The second wavelength light with wavelength λ2 enters the common optical path of Tx and Rx after DM_B. After being reflected by the fine-tracking FSM and collimated and expanded by the telescope system, it is transmitted to the space channel.

[0073] For example, combined Figure 7The signal reception process of the space laser communication device in this example is as follows: A first wavelength light with wavelength λ1 from the space channel enters the telescope system and is beam-constricted by the telescope system. The beam-constricted first wavelength light with wavelength λ1 is reflected by the fine-tuning FSM. The first wavelength light with wavelength λ1 after being reflected by the fine-tuning FSM reaches DM_B. DM_B transmits the first wavelength light with wavelength λ1 (λ1@T). The first wavelength light with wavelength λ1 after being transmitted by DM_B is incident on the nutating FSM (first fast-control mirror) and reflected by the nutating FSM to DM_A. DM_A reflects the first wavelength light with wavelength λ1 (λ1@R). The first wavelength light with wavelength λ1 reflected by DM_A is received by the photonic module.

[0074] Example 3: Figure 8 This is a schematic diagram of the structure of a photonic module provided as an example in this application.

[0075] In this example, the photonic module includes a preamplifier (PA), a power amplifier (BA), an optical mixer, a photodetector, a signal encoder, and an electro-optic modulator.

[0076] For example, the photonic module operates as follows when receiving optical signals: After the received optical signal enters the photonic module from the optical path module, it is amplified with low noise by a preamplifier before entering the photodetector to improve receiving sensitivity. The received optical signal then enters the optical mixer, where it is coupled with the local oscillator signal emitted by the local oscillator light source. The received optical signal and the local oscillator signal interfere and beat, thus converting the high-frequency received optical signal into an intermediate frequency (IF) signal. The converted IF received optical signal enters the photodetector, which converts the information-carrying received optical signal into a corresponding electrical signal, transforming the periodic fluctuations in light intensity into periodic fluctuations in current / voltage.

[0077] For example, when transmitting an optical signal, the photonic module operates as follows: A tunable laser source outputs a continuous optical carrier with tunable wavelength and stable phase. An optoelectronic modulator loads the amplitude / phase information of an electrical signal onto the optical carrier, outputting a modulated optical signal carrying communication information, i.e., the transmitted optical signal. Subsequently, a power amplifier amplifies the transmitted optical signal at high power to compensate for losses in subsequent transmission processes. Finally, the amplified transmitted optical signal is output from the photonic module's transmitter port to the optical path module.

[0078] The above description, with reference to the accompanying drawings, illustrates some embodiments of this application, but does not limit the scope of this application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and spirit of this application shall be within the scope of this application.

Claims

1. An optical path module, characterized in that, include: The first dichroic mirror is used to reflect light of the first wavelength and transmit light of the second wavelength. The second dichroic mirror is used to transmit the first wavelength light and reflect the second wavelength light. A first fast-control mirror is used to reflect the light of the first wavelength; A second fast-control mirror is used to reflect the second wavelength of light; The first dichroic mirror, the first fast-control mirror, and the second dichroic mirror form the first optical path for the first wavelength light from the first port to the second port. The first dichroic mirror, the second fast-control mirror, and the second dichroic mirror form a second optical path for the second wavelength light from the first port to the second port.

2. The optical path module according to claim 1, characterized in that, The first optical path formed by the first dichroic mirror, the first fast control mirror, and the second dichroic mirror and the second optical path formed by the first dichroic mirror, the second fast control mirror, and the second dichroic mirror partially overlap.

3. The optical path module according to claim 2, characterized in that, The optical paths of the first wavelength light and the second wavelength light overlap between the first dichroic mirror and the first port; The optical paths of the first wavelength light and the second wavelength light overlap between the second dichroic mirror and the second port.

4. The optical path module according to claim 1, characterized in that, It also includes a third fast control mirror, which is located between the second dichroic mirror and the second port.

5. The optical path module according to claim 1, characterized in that, Both the first and second fast control reflectors are equipped with advanced control and nutation control functions.

6. The optical path module according to claim 1, characterized in that, A collimator is provided between the first dichroic mirror and the first port.

7. A space laser communication device, characterized in that, include: The optical path module as described in any one of claims 1 to 6; A photonic module, which is connected to the optical path module.

8. The space laser communication device according to claim 7, characterized in that, The photonic module is connected to the optical coupling interface of the optical path module via two parallel optical fibers.

9. The space laser communication device according to claim 7, characterized in that, The photonic module includes a tunable laser source, which is used to generate light of the first wavelength or the second wavelength.

10. The space laser communication device according to claim 7, characterized in that, The photonic module includes an optical amplifier, which amplifies the first wavelength light and the second wavelength light.

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