Laser power stability control device based on Rydberg atom antenna

Abstract

The utility model provides a laser power stability control device based on a Rydberg atom antenna. The laser power stability control device comprises an adjustable optical attenuator, a PID control module, a half slide, an optical splitter, a sampling mirror and a photoelectric detector. The variable optical attenuator adjusts the attenuation degree of a received external laser signal, and then outputs the adjusted laser signal to the optical splitter after passing through the half-wave plate through the optical fiber; after the optical splitter splits the received laser signal, one beam is output to the atomic gas chamber, and the other beam is output to the photoelectric detector; the photoelectric detector converts the received laser signal into a light intensity electric signal and outputs the light intensity electric signal to the PID control module; and the PID control module performs PID algorithm adjustment according to the light intensity preset data information, and feeds back the digital control signal carrying the control quantity to the variable optical attenuator. The technical problem that under the condition that long-distance optical fiber transmission exists between the laser power stabilizing device and the atomic gas chamber, it is difficult to maintain the stability of the laser power input into the atomic gas chamber is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to laser technology field, concretely relates to a laser power stable control device based on rydberg atom antenna. BACKGROUND

[0002] In the field of laser communication research, the stability of laser power directly affects the performance of atomic cell and experimental results. The existing laser power control device generally adopts open-loop regulation or simple closed-loop feedback mechanism, including PID controller and laser attenuator, the device can control the stable laser signal output by the laser attenuator through multiple closed-loop feedback, but when the stable laser signal is transmitted to the rydberg atom cell through the optical fiber, due to the optical fiber bending loss, long distance or temperature sensitivity under the scene of large temperature difference or long distance or high power laser transmission may excite stimulated Brillouin scattering (SBS) or stimulated Raman scattering (SRS) effect, which will cause the laser power instability such as local loss fluctuation, instantaneous jump and short-term power fluctuation of the laser power input into the atomic cell, therefore, how to maintain the stability of the laser power input into the atomic cell under the condition of long distance optical fiber transmission between the laser power stabilization device and the atomic cell is a technical problem to be solved. SUMMARY

[0003] In order to overcome the defects of the prior art, the utility model provides a laser power stable control device based on rydberg atom antenna, which can realize the ultra-high stability control of laser power in complex optical fiber transmission environment, has small fluctuation, and is especially suitable for the scene of rydberg atom cell and other scenes with high requirements on light source stability, so as to solve the technical problem that it is difficult to maintain the stability of the laser power input into the atomic cell under the condition of long distance optical fiber transmission between the laser power stabilization device and the atomic cell.

[0004] The technical scheme provided by the utility model is as follows:

[0005] A laser power stable control device based on rydberg atom antenna comprises an adjustable optical attenuator and a PID control module, and further comprises a half glass plate, a beam splitter, a sampling mirror and a photoelectric detector arranged in the interior of the rydberg atom antenna; the adjustable optical attenuator, the half glass plate, the beam splitter, the sampling mirror, the photoelectric detector and the PID control module are connected in sequence and form a feedback control loop for laser power regulation.

[0006] The adjustable optical attenuator is connected with the output end of the PID control module and is connected with the optical splitter through a half-wave plate after an optical fiber, receives and adjusts the attenuation degree of the external laser signal, and then outputs the adjusted laser signal to the optical splitter through the half-wave plate after the optical fiber; the optical splitter is connected with the output end of the half-wave plate through an optical fiber, and is used for splitting the adjusted laser signal, one of which is output to the atomic chamber, and the other is output to the photoelectric detector; the photoelectric detector is connected with the output end of the optical splitter through a sampling mirror, and is used for converting the adjusted laser signal into an optical intensity electrical signal and outputting the optical intensity electrical signal to the PID control module; the PID control module is connected with the output end of the photoelectric detector and the input end of the adjustable optical attenuator, and is used for processing the optical intensity electrical signal and outputting a control signal to the adjustable optical attenuator.

[0007] Further, the PID control module comprises a receiving unit, a PID adjusting unit connected with the output end of the receiving unit, and an output unit connected with the output end of the PID adjusting unit; the PID adjusting unit processes the optical intensity electrical signal of the photoelectric detector received by the receiving unit and the control signal carrying the optical intensity preset data information, generates a control signal for adjusting the laser power, and outputs the control signal to the adjustable optical attenuator through the output unit.

[0008] Further, an analog-to-digital converter is further connected between the PID control module and the photoelectric detector, and the analog-to-digital converter converts the optical intensity electrical signal from the photoelectric detector into a digital signal and outputs the digital signal to the PID control module.

[0009] The PID control module and the adjustable optical attenuator are further connected with a digital-to-analog converter and a low-pass filter, the digital-to-analog converter converts the digital control signal output by the PID control module into an analog control signal and outputs the analog control signal to the low-pass filter, and the low-pass filter filters the analog control signal to remove high-frequency noise and outputs the analog control signal to the adjustable optical attenuator.

[0010] Further, an upper computer is further included, the upper computer is connected with the PID control module through a bus, and the upper computer is used for sending the control signal carrying the optical intensity preset data information to the PID control module.

[0011] The utility model discloses a "real-time closed loop feedback + optical fiber transmission anti-interference optimization + remote adaptive control" technical route, and the technical route solves the problem of laser power stability deterioration under long-distance optical fiber transmission scene, provides reliable light source guarantee for atomic chamber high-precision quantum sensing, atomic clock and quantum communication system, and the comprehensive performance is obviously superior to the existing open loop or simple closed loop control scheme, and the beneficial effects are as follows:

[0012] 1) The utility model discloses a real -time beam splitting monitoring laser power of optical fiber output end through beam splitter, combines the closed -loop feedback adjustment of PID control module, directly compensates the power fluctuation caused by the bending loss, temperature sensitivity and non -linearity effect in optical fiber transmission, satisfies the demand of submillihertz level light frequency shift suppression of ridberg atom precision control.

[0013] 2) The utility model discloses the light intensity error approaches to zero when the PID control module detects, locks the attenuation state of adjustable optical attenuator, realizes the long -term stable maintenance of output laser power.

[0014] 3) The beam splitter divides the laser signal after optical fiber transmission into two beams, one is directly used for atom gas chamber excitation, and the other is fed back to the photodetector, realizes in situ monitoring and control of the power of optical fiber transmission link end, avoids the limitation of " feedforward compensation depends on model prediction " in traditional scheme. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is the structure schematic diagram of the laser power stable control device based on ridberg atom antenna that the utility model discloses an embodiment. DETAILED DESCRIPTION

[0016] In order to make the person in the technical field better understand the technical scheme in the present application, the technical scheme in the present application embodiment will be described clearly and completely in the following with the drawings in the present application embodiment, obviously, the described embodiment is only a part of the present application embodiment, not all. Based on the embodiment in the present application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the scope of the present application.

[0017] As shown in the accompanying drawings, Figure 1 The utility model discloses a kind of laser power stable control devices based on ridberg atom antenna, including adjustable optical attenuator and PID control module, further including semi glass, beam splitter, sampling mirror and photodetector arranged in ridberg atom antenna inside;Adjustable optical attenuator, semi glass, beam splitter, sampling mirror, photodetector and PID control module are sequentially connected and form the feedback control loop of laser power regulation.

[0018] The adjustable optical attenuator is in communication connection with the output end of the PID control module, and is connected with the optical splitter through a half-wave plate after an optical fiber. The adjustable optical attenuator receives and adjusts the attenuation degree of the external laser signal, and then outputs the adjusted laser signal to the optical splitter through the half-wave plate after the optical fiber. In this embodiment, a high-precision MEMS (Micro-Electro-Mechanical System) adjustable optical attenuator is adopted, with an attenuation range of 0-30 dB, a resolution of 0.01 dB, a support for a digital control interface, an adaptation wavelength range of 780-1550 nm, and a coverage of the commonly used laser bands of rubidium, cesium, and Rydberg atom chambers.

[0019] The optical splitter is in communication connection with the output end of the half-wave plate through an optical fiber, and is used to split the adjusted laser signal, with one beam output to the atom chamber and the other beam output to the photodetector. In this embodiment, the optical splitter adopts an adjustable splitting ratio fiber coupler, with a splitting ratio of 1%-20% continuously adjustable, a real-time adjustment of the splitting ratio through a stepper motor or an electric control mode, and a reference photodetector integrated at the output end of the optical splitter for a regular self-calibration of the splitting ratio accuracy. The splitting ratio is adaptively adjusted according to the length and power of the optical fiber, to balance the monitoring accuracy and optical loss.

[0020] The photodetector is in communication connection with the output end of the optical splitter through a sampling mirror, and is used to convert the adjusted laser signal into an optical intensity electrical signal and output the optical intensity electrical signal to the PID control module. In this embodiment, the photodetector has a response wavelength of 800-1700 nm, a linear dynamic range of -50 dBm-+10 dBm, a detection bandwidth of DC-1 MHz, and a support for fast power fluctuation detection.

[0021] The PID control module is in communication connection with the output end of the photodetector and the input end of the adjustable optical attenuator, and is used to process the optical intensity electrical signal and output a control signal to the adjustable optical attenuator. In this embodiment, the PID control module is realized based on an FPGA or a DSP, supports floating-point operation, and has a control period of 1 μs-100 ms adjustable.

[0022] The host computer is in communication connection with the PID control module through a bus, and is used to set PID parameters and send a control signal carrying preset optical intensity data information to the PID control module. The host computer supports an RS-485 communication protocol, remotely sets a target power, PID parameters, and a splitting ratio, displays a current power, an error, a control amount, and a system state, and the like.

[0023] After multiple feedbacks, when the error between the optical intensity electrical signal received by the PID control module and the preset stable optical intensity data information tends to zero, the closed-loop feedback is stopped, the adjustable optical attenuator is maintained in a stable attenuation state, and a laser signal with a fixed frequency is output to the atom chamber.

[0024] The PID control module comprises a receiving unit, a PID adjusting unit, and an output unit.

[0025] a receiving unit configured to receive a light intensity electrical signal from the photodetector and a control signal carrying preset data information of stable light intensity;

[0026] a PID regulating unit configured to compare the light intensity electrical signal with the preset data information of stable light intensity to obtain an error value, and then calculate a control quantity and generate a digital control signal carrying the control quantity according to the error value;

[0027] an output unit configured to output the digital control signal to the adjustable optical attenuator.

[0028] The PID control module and the photodetector are further connected in communication with an analog-to-digital converter, which is configured to convert the light intensity electrical signal from the photodetector into a digital signal and then output the digital signal to the PID control module.

[0029] The PID control module and the adjustable optical attenuator are further connected with a digital-to-analog converter and a low-pass filter, the digital-to-analog converter is configured to convert the digital control signal output by the PID control module into an analog control signal and output the analog control signal to the low-pass filter, and the low-pass filter is configured to filter the analog control signal to remove high-frequency noise and output the analog control signal to the adjustable optical attenuator.

[0030] The adjustable optical attenuator, the optical splitter, the photodetector and the PID control module are connected in sequence to form a feedback control loop for laser power regulation, so that the laser power can be controlled with ultra-high stability in a complex fiber transmission environment, with a fluctuation of less than 1%, and the device is particularly suitable for scenes such as Rydberg atom chambers that have high requirements for light source stability.

[0031] The utility model embodiment based on a laser power stable control device based on Rydberg atom antenna, and its stable control process is as follows:

[0032] S01. Parameter configuration: the preset data information of stable light intensity is set remotely through the serial port communication of the upper computer, including the target power value of the adjustable optical attenuator, the PID parameters (proportion coefficient, integral time and differential time) and the control threshold.

[0033] S02. Real-time data acquisition: after the laser signal output by the adjustable optical attenuator is transmitted to the atom chamber through the optical fiber, a part of the laser signal is output to the photodetector through the optical splitter, and the photodetector converts the received laser signal into a light intensity electrical signal and then outputs the light intensity electrical signal to the PID control module. The photodetector measures the output power of the optical splitter, and the analog-to-digital conversion module converts the analog signal into a digital quantity and transmits the digital quantity to the PID control module.

[0034] S03. PID dynamic adjustment: After the PID control module receives the light intensity electrical signal, it compares the light intensity electrical signal with the stable light intensity preset data information according to the light intensity preset data information, obtains an error value, and then calculates a control amount according to the error value through three links of proportion, integration, and differentiation, generates a digital control signal, converts it into an analog control signal such as a voltage or current signal through a digital-to-analog conversion module, filters it through a low-pass filter, and outputs it to the adjustable optical attenuator; the adjustable optical attenuator adjusts the control amount of laser attenuation and outputs the laser signal to the atomic cell, adjusts the optical attenuation amount, and when performing PID operation, dynamically updates the three PID parameters of the proportional coefficient, integral time, and differential time according to the fiber length L and the transmission power P, and performs anti-saturation integration and filter differentiation calculation; the digital-to-analog conversion module DAC converts the digital control amount into an analog signal; the low-pass filter smooths the output to drive the adjustable optical attenuator to adjust the attenuation degree.

[0035] S04. Power closed-loop feedback: The photodetector collects the updated power value of the adjustable optical attenuator output laser again to form a closed-loop feedback and continuously iteratively optimize the control amount.

[0036] S05. Stability determination: When the error between the light intensity electrical signal received by the PID control module and the stable light intensity preset data information approaches zero, the closed-loop feedback is stopped and the adjustable optical attenuator is maintained in a stable attenuation state at all times, and a fixed frequency laser signal is output to the atomic cell.

Claims

1.A laser power stable control device based on a Rydberg atom antenna, comprising an adjustable optical attenuator and a PID control module, characterized in that, further comprising a half-wave plate, a beam splitter, a sampling mirror and a photodetector arranged inside the Rydberg atom antenna; the adjustable optical attenuator, the half-wave plate, the beam splitter, the sampling mirror, the photodetector and the PID control module are connected in sequence and form a feedback control loop for laser power adjustment. Wherein, the adjustable optical attenuator is in communication connection with the output end of the PID control module, and is connected with the beam splitter through an optical fiber after passing through the half-wave plate, receives and adjusts the attenuation degree of the external laser signal, and then outputs the adjusted laser signal to the beam splitter through an optical fiber after passing through the half-wave plate; the beam splitter is in communication connection with the output end of the half-wave plate through an optical fiber, and is used for splitting the adjusted laser signal, one of which is output to the atomic chamber, and the other is output to the photodetector; the photodetector is in communication connection with the output end of the beam splitter through the sampling mirror, and is used for converting the adjusted laser signal into an optical intensity electrical signal and outputting it to the PID control module; the PID control module is in communication connection with the output end of the photodetector and the input end of the adjustable optical attenuator, and is used for processing the optical intensity electrical signal and outputting a control signal to the adjustable optical attenuator. 2.The laser power stable control device based on a Rydberg atom antenna according to claim 1, characterized in that, the PID control module comprises a receiving unit, a PID adjusting unit in communication connection with the output end of the receiving unit, and an output unit in communication connection with the output end of the PID adjusting unit; the PID adjusting unit processes the optical intensity electrical signal of the photodetector received by the receiving unit and the control signal carrying the optical intensity preset data information, and generates a control signal for adjusting the laser power, which is output to the adjustable optical attenuator through the output unit. 3.The laser power stable control device based on a Rydberg atom antenna according to claim 1 or 2, characterized in that, an analog-to-digital converter is further in communication connection between the PID control module and the photodetector, which converts the optical intensity electrical signal from the photodetector into a digital signal and outputs it to the PID control module; a digital-to-analog converter and a low-pass filter are further connected between the PID control module and the adjustable optical attenuator, the digital-to-analog converter converts the digital control signal output by the PID control module into an analog control signal and outputs it to the low-pass filter, the low-pass filter filters the analog control signal to remove high-frequency noise and outputs it to the adjustable optical attenuator. 4.The laser power stable control device based on a Rydberg atom antenna according to claim 3, characterized in that, further comprising a host computer, which is in communication connection with the PID control module through a bus, and is used for sending a control signal carrying optical intensity preset data information to the PID control module. ​ ​ ​ ​

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