Polarization controlled laser power quantum stabilization apparatus, method, laser emitting device

Abstract

The specification discloses a polarization control laser power quantum stabilization device, method and laser emitting equipment to improve the stability of laser power. The device comprises a laser power adjusting unit configured to adjust the laser polarization state of linearly polarized light output by a laser by using a polarization controller, and output the to-be-stabilized power laser after polarization maintaining transmission; and a feedback control unit configured to take the to-be-stabilized power laser as a monitoring object, introduce it into an atomic clock, change the output frequency of the atomic clock, and adjust the laser polarization state in the laser power adjusting unit based on the deviation between the output frequency and a given output frequency by using a feedback control method to stabilize the power of the output laser. The device has strong environmental interference resistance, reduces the influence of laser polarization change in the traditional method on power stability, improves the sensitivity and response capability of the system to small changes in stable power, and more accurately controls the stable laser power.

Description

Technical Field

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

[0002] The output power of a laser exhibits random fluctuations and long-term drift. For different types of lasers, these fluctuations may be due to poor power supply filtering, dust particles diffusing into the laser beam from the resonant cavity, vibration of the resonant cavity mirrors, or mode competition. Long-term drift may originate from temperature changes, degradation of the optical quality of mirrors and other optical components within the resonant cavity, etc. Fluctuations in laser power can affect system performance as noise, causing problems for many spectroscopic applications. Therefore, it is essential to implement solutions for accurate measurement and long-term stable control of laser power.

[0003] Currently, photodetectors are commonly used devices in experiments to measure output optical signals. However, dust particles passing through the light beam and scattered light from moving surfaces can cause fluctuations in the detected photocurrent. Beam jitter on the photodiode can also cause significant power noise due to the non-uniformity of the photodiode's responsivity.

[0004] Therefore, a more stable and reliable laser power stabilization solution is needed. Summary of the Invention

[0005] To reduce the impact of polarization on laser power and improve the stability of laser power, one aspect of the present invention proposes a polarization-controlled laser power quantum stabilization device, including a laser power adjustment unit and a feedback control unit.

[0006] The laser power adjustment unit is configured to adjust the polarization state of the linearly polarized light output by the laser using a polarization controller, and output the laser with the power to be stabilized after polarization-maintaining transmission.

[0007] The feedback control unit is configured to use the laser power to be stabilized output after polarization-maintaining transmission in the laser power adjustment unit as the monitoring object, and to input it into the atomic clock so that the output frequency of the atomic clock changes accordingly. Based on the deviation between the output frequency and the given output frequency, the laser polarization state in the laser power adjustment unit is adjusted by the feedback control method to stabilize the output laser power.

[0008] In some preferred embodiments, the laser power adjustment unit includes a polarization controller, a polarization-maintaining transmission device, and a beam splitter;

[0009] The polarization controller is configured to adjust the laser polarization state of the linearly polarized light output by the laser.

[0010] 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.

[0011] The beam splitter is configured to split the laser beam transmitted by the polarization-maintaining transmission device into two beams by interference of a mirror.

[0012] In some preferred embodiments, the feedback control unit includes an atomic clock, a frequency counter, and a feedback control module;

[0013] The atomic clock is configured to generate the output frequency corresponding to one of the laser beams after the beam is split by the beam splitter.

[0014] The frequency counter is configured to collect the output frequency information of the atomic clock;

[0015] The feedback control module is configured to acquire the frequency information collected by the frequency counter, obtain the deviation between the frequency and the given output frequency, and generate the adjustment amount of the polarization controller.

[0016] In some preferred embodiments, the polarization-maintaining transmission device is a polarization-maintaining optical fiber.

[0017] In some preferred embodiments, the beam-splitting device is a beam-splitting prism.

[0018] 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.

[0019] In some preferred embodiments, the feedback control module is a PID feedback control module.

[0020] A second aspect of the present invention provides a polarization-controlled laser power quantum stabilization method, based on the aforementioned polarization-controlled laser power quantum stabilization device, the method comprising:

[0021] The linearly polarized light output from the laser is adjusted using a polarization controller according to preset values.

[0022] After polarization-preserving 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.

[0023] The second laser beam is introduced into the atomic clock, causing its output frequency to change accordingly. Based on the deviation between this output frequency and the given output frequency, the laser polarization state in the laser power adjustment unit is adjusted through a feedback control method to stabilize the output laser power.

[0024] In some preferred embodiments, adjusting the laser polarization state in the laser power adjustment unit includes:

[0025] The angle between the polarization direction of the incident light and the optical axis in the polarization-maintaining transmission device.

[0026] A third aspect of the present invention provides a power-stable laser emitting device, characterized in that it includes a laser and the aforementioned polarization-controlled laser power quantum stabilization device.

[0027] The above-described at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects:

[0028] This invention utilizes the interference of different polarization components of a beam of light in a polarization-maintaining optical fiber, which serves as the polarization-maintaining transmission medium, to measure and stabilize the laser power using an atomic clock. Compared with existing laser power stabilization methods, this method has higher detection sensitivity and accuracy, stronger resistance to environmental interference, reduces the impact of laser polarization changes on power stability in traditional methods, improves the system's sensitivity and response to small changes in stable power, and enables more precise control of stable laser power. Attached Figure Description

[0029] 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:

[0030] Figure 1 A schematic diagram of a polarization-controlled laser power quantum stabilization device provided in one embodiment of this specification;

[0031] Figure 2 A schematic diagram of a polarization-controlled laser power quantum stabilization device is provided as another embodiment of this specification.

[0032] Figure 3 This is a schematic flowchart of a polarization-controlled laser power quantum stabilization method provided in one embodiment of this specification. Detailed Implementation

[0033] 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.

[0034] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0035] An atomic clock is a device that uses the electromagnetic waves emitted when atoms absorb or release energy to keep time. It is the most accurate known time measurement and frequency standard in the world, with high stability; currently reported long-term stability of atomic clocks reaches the order of 10⁻¹⁸. When atomic energy levels are affected by external near-resonant pump light, energy level shifts occur. The amount of shift is related to the frequency and intensity of the pump light, causing a change in the atomic clock's output frequency. Therefore, changes in the atomic clock's output frequency can reflect changes in the laser power introduced into the atomic clock.

[0036] Optical fiber has been widely used due to its advantages such as low cost and strong anti-interference capability. Polarization-maintaining fiber, as a special type of fiber, exhibits a strong birefringence effect, resulting in different phase delays for the two components of linearly polarized light propagating within the fiber. Therefore, polarization interference of the two components of a linearly polarized light beam can be achieved using polarization-maintaining fiber, causing a change in the combined optical power at the fiber's tail end. By controlling the polarization direction of the laser transmitted into the fiber, the optical power at the fiber's output end can be controlled.

[0037] This invention proposes to use optical fiber to achieve polarization interference. Based on the interferometric measurement results, an atomic clock and a frequency counter are used to represent the power of the laser to be stabilized as the output frequency of the atomic clock. Based on the feedback control method, a feedback control unit and a laser power adjustment unit are combined to form a closed-loop control circuit. Based on the frequency deviation between the atomic clock output frequency and the preset output laser power, the change in laser polarization direction is obtained, the polarization controller is adjusted, and finally the optical power at the output end of the optical fiber is changed.

[0038] Figure 1 This specification provides a schematic diagram of a polarization-controlled laser power quantum stabilization device according to an embodiment. The device may specifically include a laser power adjustment unit and a feedback control unit. The laser power adjustment unit is configured to adjust the polarization state of the linearly polarized light output from the laser using a polarization controller, and output the laser power to be stabilized after polarization-maintaining transmission. The feedback control unit is configured to use the laser power to be stabilized output after polarization-maintaining transmission in the laser power adjustment unit as a monitoring object, guide it to an atomic clock, causing the atomic clock output frequency to change accordingly. Based on the deviation between this output frequency and a given output frequency, the feedback control method is used to adjust the laser polarization state in the laser power adjustment unit to stabilize the output laser power.

[0039] To provide a detailed explanation of the polarization-controlled laser power quantum stabilization device of the present invention, the following is in conjunction with... Figure 2 The specific structure of the device of the present invention will be described in detail below. The polarization-controlled laser power quantum stabilization device in this embodiment includes a laser power adjustment unit and a feedback control unit. The feedback control unit and the laser power adjustment unit form a closed-loop control circuit to stabilize the output laser power.

[0040] The laser power adjustment unit includes a polarization controller, a polarization-maintaining transmission device, and a beam splitter connected in sequence. The polarization controller is configured to adjust the polarization state of the linearly polarized light output from the laser; the polarization-maintaining transmission device is configured to generate a phase delay in the polarization components parallel to and perpendicular to the optical axis of the linearly polarized light; and the beam splitter is configured to split the laser beam transmitted through the polarization-maintaining transmission device into two beams via interference from a mirror. In this embodiment, a 795nm laser is used; the polarization-maintaining transmission device is a polarization-maintaining fiber; and the beam splitter is a beam splitter prism.

[0041] During operation, the linearly polarized light output from the 795nm laser is polarized by a polarization controller, which couples the output linearly polarized light into a polarization-maintaining fiber. In the polarization-maintaining fiber, the polarization components of the linearly polarized light parallel to and perpendicular to the optical axis produce a phase delay. After being transmitted through the polarization-maintaining fiber, the linearly polarized light is interfered by a beam splitter prism and split into two paths. One path is used for output to meet actual needs, while the other path is coupled into an atomic clock in the feedback control unit.

[0042] The feedback control unit includes an atomic clock, a frequency counter, and a feedback control module connected in sequence. The atomic clock is configured to generate the output frequency corresponding to one laser beam after beam splitting by the beam splitter; the frequency counter is configured to collect the output frequency information of the atomic clock; the feedback control module is configured to acquire the frequency information collected by the frequency counter, obtain the deviation between the frequency information and the given output frequency, and generate the adjustment amount for the polarization controller. Here, the adjustment amount for 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. In this embodiment, the feedback control module is a PID feedback control module.

[0043] During operation, the output frequency of the atomic clock changes accordingly based on the laser coupled into it. The frequency counter collects the output frequency information of the atomic clock and transmits it to the feedback control module. The feedback control module calculates the deviation between the monitored atomic clock output frequency information and the given output frequency. After processing by the PID feedback control algorithm, the output error compensation signal is used as the adjustment amount of the polarization controller and fed back to the polarization controller. This causes the polarization controller to change the angle between the polarization direction of the incident light 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.

[0044] A second embodiment of the present invention provides a polarization-controlled laser power quantum stabilization method, based on the aforementioned polarization-controlled laser power quantum stabilization device, the method as follows: Figure 3 As shown, it includes:

[0045] S100 adjusts the polarization state of the linearly polarized light output from the laser according to a preset value using a polarization controller.

[0046] S200: 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.

[0047] S300, the second laser beam is introduced into the atomic clock, causing its output frequency to change accordingly. Based on the deviation between the output frequency and the given output frequency, the laser polarization state in the laser power adjustment unit is adjusted by a feedback control method to stabilize the output laser power.

[0048] In this embodiment, the laser polarization state in the laser power adjustment unit 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.

[0049] A laser emitting device according to a third embodiment of the present invention includes a laser and the above-described polarization-controlled laser power quantum stabilization device.

[0050] 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 quantum stabilization method, laser emitting device, and related methods described above can be found in the corresponding content of the aforementioned polarization-controlled laser power quantum stabilization device embodiments, and will not be repeated here.

[0051] 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.

[0052] 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).

[0053] 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 the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0054] The terms “first”, “second”, etc., are used to distinguish similar objects, not to describe or indicate a specific order or sequence.

[0055] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0056] 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 quantum stabilization device, characterized by, Includes a laser power adjustment unit and a feedback control unit; The laser power adjustment unit is configured to adjust the polarization state of the linearly polarized light output by the laser using a polarization controller, and output the laser with the power to be stabilized after polarization-maintaining transmission. The feedback control unit is configured to use the laser power to be stabilized output after polarization-maintaining transmission in the laser power adjustment unit as the monitoring object, and to input it into the atomic clock so that the output frequency of the atomic clock changes accordingly. Based on the deviation between the output frequency and the given output frequency, the laser polarization state in the laser power adjustment unit is adjusted by the feedback control method to stabilize the output laser power. in, The laser power adjustment unit 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 by interference of a mirror. The feedback control unit includes an atomic clock, a frequency counter, and a feedback control module; The atomic clock is configured to generate the output frequency corresponding to one of the laser beams after the beam is split by the beam splitter. The frequency counter is configured to collect the output frequency information of the atomic clock; The feedback control module is configured to acquire the frequency information collected by the frequency counter, obtain the deviation between the frequency and the given output frequency, and generate the adjustment amount of the polarization controller. The polarization-maintaining transmission device is a polarization-maintaining optical fiber; The beam-splitting device is a beam-splitting prism; 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. The feedback control module is a PID feedback control module.

2. A polarization controlled method of quantum stabilization of laser power, characterized in that, Based on the polarization-controlled laser power quantum stabilization device according to claim 1, the method includes: The linearly polarized light output from the laser is adjusted using a polarization controller 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. The second laser beam is introduced into the atomic clock, causing its output frequency to change accordingly. Based on the deviation between this output frequency and the given output frequency, the laser polarization state in the laser power adjustment unit is adjusted through a feedback control method to stabilize the output laser power. in, Adjusting the laser polarization state in the laser power adjustment unit includes: The angle between the polarization direction of the incident light and the optical axis in the polarization-maintaining transmission device.

3. A laser emitting device, characterized by, It includes a laser, and the laser power quantum stabilization device with polarization control as described in claim 1.

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