Polarization-controlled laser power stabilization control device, method, and laser emitting equipment

Abstract

This specification discloses a polarization-controlled laser power stabilization control device, method, and laser emitting equipment to improve laser power stability. The device includes a first branch and a second branch. The first branch is configured to adjust the polarization state of the linearly polarized light output from the laser and output the laser power to be stabilized after polarization-maintaining transmission. The second branch is a feedback adjustment branch that uses the laser power to be stabilized output from the first branch after polarization-maintaining transmission as a monitoring signal. After photoelectric signal conversion by a photoelectric detection device, the polarization state of the laser in the first branch is adjusted through a closed-loop control method to stabilize the output laser power. The device is low-cost, has a simple system structure, and is insensitive to environmental changes such as external vibrations. It reduces the impact of environmental noise and polarization on power stability in laser power stabilization control, thereby improving laser power stability.

Description

Technical Field

[0001] This document relates to the field of optoelectronic technology, and in particular to a polarization-controlled laser power stabilization control device, method, and laser emitting equipment. Background Technology

[0002] Highly stable lasers are indispensable tools in many modern experimental techniques, but fluctuations in laser power manifest as power noise, affecting system performance and sensitivity. Therefore, improving laser power stability is an essential technique. Current methods for stabilizing laser power primarily involve modulating the laser output power externally using acousto-optic modulators or electro-optic modulators. However, these methods are sensitive to changes in laser polarization and have weak resistance to environmental interference.

[0003] Therefore, a more stable and reliable laser power stabilization solution is needed. Summary of the Invention

[0004] In order to reduce environmental noise and the influence of polarization on power stability in laser power stabilization control, and improve the stability of laser power, one aspect of the present invention proposes a polarization-controlled laser power stabilization control device, including a first branch and a second branch.

[0005] The first branch is configured to adjust the laser polarization state of the linearly polarized light output by the laser, and output the laser of the power to be stabilized after polarization-maintaining transmission;

[0006] The second branch is a feedback adjustment branch. The laser power to be stabilized output after polarization-maintaining transmission in the first branch is used as a monitoring signal. After photoelectric signal conversion by the photoelectric detection device, the polarization state of the laser in the first branch is adjusted by a closed-loop control method to stabilize the output laser power.

[0007] In some preferred embodiments, the first branch includes a polarization controller, a polarization-maintaining transmission device, and a beam splitter;

[0008] The polarization controller is configured to adjust the laser polarization state of the linearly polarized light output by the laser.

[0009] The polarization-maintaining transmission device is configured to generate a phase delay for the polarization components of linearly polarized light parallel to and perpendicular to the optical axis.

[0010] The beam splitter is configured to split the laser beam transmitted by the polarization-maintaining transmission device into two beams through interference.

[0011] In some preferred embodiments, the polarization-maintaining transmission device is a polarization-maintaining optical fiber.

[0012] In some preferred embodiments, the beam-splitting device is a beam-splitting prism.

[0013] In some preferred embodiments, the second branch includes a photodetector and a feedback control unit;

[0014] The photodetector is configured to convert one of the laser beams split by the beam splitter into photoelectric signals.

[0015] The feedback control unit is configured to acquire the electrical signal output by the photodetector, obtain the deviation corresponding to the given laser power value, and generate the adjustment amount of the polarization controller.

[0016] In some preferred embodiments, the adjustment amount of the polarization controller includes the angle between the polarization direction of the incident light from the polarization-maintaining transmission device and the optical axis of the polarization-maintaining transmission device.

[0017] In some preferred embodiments, the feedback control unit is a PID feedback control unit.

[0018] A second aspect of the present invention provides a polarization-controlled laser power stabilization control method, based on the aforementioned polarization-controlled laser power stabilization control device, the method comprising:

[0019] The laser polarization state of the linearly polarized light output by the laser is adjusted according to preset values;

[0020] After polarization-maintaining transmission, linearly polarized light is interfered with and split into beams by a beam splitter. The first laser beam is used for output, and the second laser beam is used for power monitoring.

[0021] After the second laser beam undergoes photoelectric signal conversion by the photoelectric detection device, the polarization state of the laser in the first branch is adjusted according to the detection results through a closed-loop control method to stabilize the output laser power.

[0022] In some preferred embodiments, the laser polarization state in the first branch is adjusted, including:

[0023] The angle between the polarization direction of the incident light and the optical axis in the polarization-maintaining transmission device.

[0024] In a third aspect, the present invention provides a power-stable laser emitting device, characterized in that it includes a laser and the aforementioned polarization-controlled laser power stabilization control device.

[0025] The above-described at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects:

[0026] This invention proposes a device for achieving interference and stable control of laser power using different polarization components of a single beam of light within a polarization-maintaining fiber, which serves as the polarization-maintaining transmission medium. Since the two polarization components follow the same paths and experience the same environmental changes, the synthesized polarized light is insensitive to environmental noise, avoiding the influence of the external environment on the two signals found in a Michelson interferometer. This reduces the impact of environmental noise and polarization on power stability during laser power stabilization control, improves the system's sensitivity and response to minute power changes, enhances its resistance to external environmental interference, and improves laser power stability, providing a novel approach for stable laser power control. Furthermore, the choice of polarization-maintaining fiber significantly reduces system cost and experimental difficulty.

[0027] The device of this invention has low cost, simple system structure, and is not sensitive to environmental changes such as external vibration. It reduces the impact of environmental noise and polarization on power stability in laser power stabilization control and improves the stability of laser power. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0029] Figure 1 A schematic diagram of a polarization-controlled laser power stabilization control device provided in one embodiment of this specification;

[0030] Figure 2 A schematic diagram of a polarization-controlled laser power stabilization control device is provided for another embodiment of this specification.

[0031] Figure 3 This is a schematic flowchart of a polarization-controlled laser power stabilization control method provided in one embodiment of this specification. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0034] This invention proposes to use optical fiber to achieve polarization interference, and to change the laser polarization direction based on the interference measurement results, thereby changing the optical power at the output end of the optical fiber.

[0035] Optical fiber has been widely used due to its advantages of low cost, high sensitivity, and strong anti-interference capability. In optical fiber communication, optical fiber is usually used as a transmission medium to transmit information. With the development of optical fiber communication technology, optical fiber sensors, as a new type of sensing technology, have attracted widespread attention. Optical fiber sensors are a new type of sensing technology that uses optical fiber as a medium to sense and transmit changes in external quantities. When external light acts on the optical fiber, the measured quantity will change some characteristics of the light transmitted within the fiber. Fiber optic sensors based on the Michelson interferometer structure and the Sagnac interference principle have been applied in many fields such as national defense and scientific research. In practical work, the two arms of the optical fiber sensor based on the Michelson interferometer structure must change in sync with the changes in environmental noise; otherwise, the measurement results will be affected. In addition, changes in the external environment may change the polarization state of the laser, which may cause destructive interference, resulting in the disappearance of the interference signal. Furthermore, the experimental setup for optical fiber sensors based on the Sagnac structure is highly complex.

[0036] Polarization-maintaining fiber possesses birefringence properties. When linearly polarized light passes through it, it splits into ordinary and extraordinary components. Since these components have different refractive indices, a phase difference exists between them at the fiber's tail end, causing a change in the power of the resulting linearly polarized light. Based on this principle, polarization-maintaining fiber can be used as a sensor to achieve interference between the two polarization components. The result can then be used to control the laser polarization direction input to the fiber, thereby regulating the output power. Currently, no literature exists on using polarization-maintaining fiber to interfere with the two polarization components of a single beam and then using the interference result to change the laser polarization direction to ultimately control the output power of the fiber.

[0037] Figure 1 This specification provides a schematic diagram of a polarization-controlled laser power stabilization control device according to an embodiment. The device may specifically include a first branch and a second branch. The first branch is configured to adjust the polarization state of the linearly polarized light output from the laser, and output the laser power to be stabilized after polarization-maintaining transmission. The second branch is a feedback adjustment branch, which uses the laser power to be stabilized output from the first branch after polarization-maintaining transmission as a monitoring signal. After photoelectric signal conversion by a photoelectric detection device, the polarization state of the laser in the first branch is adjusted through a closed-loop control method to stabilize the output laser power.

[0038] To provide a detailed description of the polarization-controlled laser power stabilization control device of the present invention, the following is in conjunction with... Figure 2The specific structure of the device of the present invention will be described in detail below. The polarization-controlled laser power stabilization control device in this embodiment includes a polarization controller, a polarization-maintaining transmission device, a beam splitter, a photodetector, and a feedback control unit; the first branch consisting of the polarization controller, the polarization-maintaining transmission device, and the beam splitter, together with the second branch consisting of the photodetector and the feedback control unit, form a closed-loop control to stabilize the output laser power.

[0039] A polarization controller is configured to adjust the polarization state of linearly polarized light output from a laser; a polarization-maintaining transmission device is configured to generate a phase delay in the polarization components of the linearly polarized light parallel to and perpendicular to the optical axis; a beam splitter is configured to split the laser transmitted through the polarization-maintaining transmission device into two beams through interference; a photodetector is configured to perform photoelectric signal conversion on one of the beams split by the beam splitter; and a feedback control unit is configured to acquire the electrical signal output by the photodetector, obtain the deviation corresponding to a given laser power value, and generate the adjustment amount of the polarization controller. Here, the adjustment amount of the polarization controller includes the angle between the polarization direction of the incident light from the polarization-maintaining transmission device and the optical axis of the polarization-maintaining transmission device.

[0040] In this embodiment, a 795nm laser is used; the polarization-maintaining transmission device is a polarization-maintaining fiber; the beam splitting device is a beam splitting prism; and the feedback control unit is a PID feedback control unit.

[0041] During operation, the linearly polarized light output from the 795nm laser is polarized by a polarization controller, which transmits the output linearly polarized light to a polarization-maintaining fiber. In the polarization-maintaining fiber, the polarization components parallel and perpendicular to the optical axis of the linearly polarized light experience phase delay. After transmission through the polarization-maintaining fiber, the linearly polarized light is interfered with by a beam splitter prism, splitting the laser into two paths. One path is used for output and meets practical needs, while the other path is coupled into a photodetector. The photodetector monitors the laser power and transmits the monitoring result to a feedback control unit. Based on the monitored laser power, the feedback control unit calculates the deviation from the given laser power, obtains the adjustment amount for the polarization controller, and feeds it back to the polarization controller. This causes the polarization controller to change the angle between the incident light polarization direction and the optical axis of the polarization-maintaining fiber, thereby changing the laser power at the output end of the polarization-maintaining fiber and achieving stable power control.

[0042] A polarization-controlled laser power stabilization control method according to a second embodiment of the present invention, based on the above-described polarization-controlled laser power stabilization control device, the method as follows: Figure 3As shown, the process includes: adjusting the laser polarization state of the linearly polarized light output by the laser according to a preset value; after polarization-maintaining transmission, the linearly polarized light is interfered and split into beams by a beam splitter, wherein the first laser beam is used for output and the second laser beam is used for power monitoring; after the second laser beam undergoes photoelectric signal conversion by a photoelectric detection device, the laser polarization state in the first branch is adjusted according to the detection result through a closed-loop control method to stabilize the output laser power.

[0043] In this embodiment, the laser polarization state in the first branch is adjusted, including the angle between the incident light polarization direction and the optical axis in the polarization-maintaining transmission device during polarization-maintaining transmission.

[0044] A third embodiment of the present invention provides a power-stabilized laser emitting device, comprising a laser and the aforementioned polarization-controlled laser power stabilization control device.

[0045] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the polarization-controlled laser power stabilization control method and the power-stabilized laser emitting device described above can be found in the corresponding content of the aforementioned polarization-controlled laser power stabilization control device embodiments, and will not be repeated here.

[0046] Specifically, according to embodiments of this disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication component, and / or installed from a removable medium. When the computer program is executed by a central processing unit (CPU), it performs the functions defined in the methods of this application. It should be noted that the computer-readable medium described above in this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in connection with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on a computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0047] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0048] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, may...

[0049] It can be implemented using a dedicated hardware-based system that performs the specified functions or operations, or it can be implemented using a combination of dedicated hardware and computer instructions.

[0050] The terms “first”, “second”, etc., are used to distinguish similar objects, not to describe or indicate a specific order or sequence.

[0051] The term "include" or any other similar term is intended to cover non-exclusive inclusion, thereby including a series of...

[0052] The elements of a process, method, article, or apparatus include not only those elements but also other elements not expressly listed, or elements inherent in those processes, methods, articles, or apparatuses.

[0053] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the above description is merely an embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A polarization-controlled laser power stabilization control device, characterized in that, Including the first branch road and the second branch road; The first branch is configured to adjust the laser polarization state of the linearly polarized light output by the laser, and output the laser of the power to be stabilized after polarization-maintaining transmission; The second branch is a feedback adjustment branch. The laser power to be stabilized output after polarization-maintaining transmission in the first branch is used as a monitoring signal. After photoelectric signal conversion by the photoelectric detection device, the polarization state of the laser in the first branch is adjusted by the closed-loop control method to stabilize the output laser power. The first branch includes a polarization controller, a polarization-maintaining transmission device, and a beam splitter. The polarization controller is configured to adjust the laser polarization state of the linearly polarized light output by the laser. The polarization-maintaining transmission device is configured to generate a phase delay for the polarization components of linearly polarized light parallel to and perpendicular to the optical axis. The beam splitter is configured to split the laser beam transmitted by the polarization-maintaining transmission device into two beams through interference. The second branch includes a photodetector and a feedback control unit; The photodetector is configured to convert one of the laser beams split by the beam splitter into photoelectric signals. The feedback control unit is configured to acquire the electrical signal output by the photodetector, obtain the deviation corresponding to the given laser power value, and generate the adjustment amount of the polarization controller.

2. The polarization-controlled laser power stabilization control device as described in claim 1, characterized in that, The polarization-maintaining transmission device is a polarization-maintaining optical fiber.

3. The polarization-controlled laser power stabilization control device as described in claim 1, characterized in that, The beam-splitting device is a beam-splitting prism.

4. The polarization-controlled laser power stabilization control device as described in claim 1, characterized in that, The adjustment amount of the polarization controller includes the angle between the polarization direction of the incident light from the polarization-maintaining transmission device and the optical axis of the polarization-maintaining transmission device.

5. The polarization-controlled laser power stabilization control device as described in claim 1, characterized in that, The feedback control unit is a PID feedback control unit.

6. A polarization-controlled laser power stabilization control method, characterized in that, The laser power stabilization control device based on the polarization control according to any one of claims 1-5, the method comprising: The laser polarization state of the linearly polarized light output by the laser is adjusted according to preset values; After polarization-maintaining transmission, linearly polarized light is interfered with and split into beams by a beam splitter. The first laser beam is used for output, and the second laser beam is used for power monitoring. After the second laser beam undergoes photoelectric signal conversion by the photoelectric detection device, the polarization state of the laser in the first branch is adjusted according to the detection results through a closed-loop control method to stabilize the output laser power. Wherein, the linearly polarized light, after polarization-maintaining transmission, is interfered with and split by a beam splitter, including: The polarization components of linearly polarized light parallel to and perpendicular to the optical axis are delayed in phase. The laser beam that produces a phase delay is split into two beams after interference; The method of adjusting the laser polarization state in the first branch through closed-loop control includes: One of the laser beams split by the beam splitter is converted into an electrical signal by photoelectric signal conversion. The adjustment amount of the polarization controller is generated based on the deviation between the electrical signal and the given laser power value.

7. The polarization-controlled laser power stabilization control method as described in claim 6, characterized in that, Adjusting the laser polarization state in the first branch includes: The angle between the polarization direction of the incident light and the optical axis in the polarization-maintaining transmission device.

8. A power-stable laser emitting device, characterized in that, It includes a laser, and a laser power stabilization control device with polarization control as described in any one of claims 1-5.

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