CN-122026218-A - Laser power control system and method with multiple time scales

CN122026218ACN 122026218 ACN122026218 ACN 122026218ACN-122026218-A

Abstract

The application provides a laser power control system and method with multiple time scales, and relates to the fields of laser technology and optical control. The system comprises a laser, a main controller, a light modulation module, a light splitting sheet and a photoelectric detector, wherein the main controller obtains a control signal of a first time scale and a control signal of a second time scale according to a laser power signal detected by the photoelectric detector, the control signal of the first time scale is sent to the laser to enable the laser to conduct corresponding power fluctuation compensation based on the control signal of the first time scale, the control signal of the second time scale is sent to the light modulation module to enable the light modulation module to conduct corresponding power fluctuation compensation based on the control signal of the second time scale. The application can realize the broadband stabilization of laser output power from direct current to high frequency through the multi-time scale graded compensation of the light modulation module and the laser, simultaneously reduce the thermal disturbance of the laser, break through the performance limit of a single regulating mechanism and improve the long-term stability and the universality of the system.

Inventors

LIN SUYING
XU ZHIHONG
WANG CHENGQIANG
ZHANG XING
LIN ZONGZHI
CHEN WEI
CHEN QIUHUA

Assignees

福建福晶科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260211

Claims (10)

1. The multi-time-scale laser power control system is characterized by comprising a laser, a main controller, an optical modulation module, a beam splitter and a photoelectric detector; The light modulation module is arranged on a transmission light path between the light emitting surface of the laser and the light entering surface of the light splitting sheet, the first light emitting surface of the light splitting sheet faces towards the detection end of the photoelectric detector, and the second light emitting surface of the light splitting sheet is used for outputting laser signals; The main controller is used for determining a power error signal according to the laser power signal detected by the photoelectric detector, and performing time scale division according to the power error signal to obtain a first time scale control signal and a second time scale control signal, wherein the power fluctuation bandwidth corresponding to the first time scale is lower than the power fluctuation bandwidth corresponding to the second time scale; The main controller is further used for sending the control signal of the first time scale to the laser, so that the laser performs corresponding power fluctuation compensation based on the control signal of the first time scale; The main controller is further configured to send the control signal of the second time scale to the optical modulation module, so that the optical modulation module performs corresponding power fluctuation compensation based on the control signal of the second time scale.
2. The system of claim 1, wherein the light modulation module comprises at least two drive controllers and at least two acousto-optic modulators, each of the drive controllers being electrically connected to one of the acousto-optic modulators; At least two acousto-optic modulators are sequentially arranged in series on a transmission light path between the light emergent surface of the laser and the light incident surface of the light splitting sheet; The main controller is connected with the control end of each driving controller, so that the driving controllers send control signals of the second time scale to the driving controllers, the driving controllers send corresponding sound wave control signals to corresponding sound wave modulators based on the control signals of the second time scale, and the sound wave modulators are used for carrying out corresponding power fluctuation compensation based on the sound wave control signals.
3. The system of claim 2, wherein the drive controller comprises a first drive controller and a second drive controller, the acousto-optic modulator comprising a first acousto-optic modulator and a second acousto-optic modulator; The first acousto-optic modulator and the second acousto-optic modulator are sequentially connected in series on a transmission light path between the light emitting surface of the laser and the light entering surface of the light splitting sheet; The second time scale comprises a first sub-time scale and a second sub-time scale, wherein the power fluctuation bandwidth corresponding to the first sub-time scale is lower than the power fluctuation bandwidth corresponding to the second sub-time scale; The main controller is connected with the control end of the first driving controller to send the control signal of the first sub-time scale to the first driving controller, so that the first driving controller sends a first sound wave control signal to the first sound-light modulator based on the control signal of the first sub-time scale, and the first sound-light modulator is used for carrying out corresponding power fluctuation compensation based on the first sound wave control signal; The main controller is connected with the control end of the second driving controller so as to send the control signal of the second sub-time scale to the second driving controller, so that the second driving controller sends a second sound wave control signal to the second sound wave modulator based on the control signal of the second sub-time scale, and the second sound wave modulator is used for carrying out corresponding power fluctuation compensation based on the second sound wave control signal.
4. The system of claim 1, wherein the laser comprises a laser power supply, a laser chip; The main controller is used for sending the control signal of the first time scale to the laser power supply, so that the laser power supply adjusts output current based on the control signal of the first time scale to compensate corresponding power fluctuation of the laser chip.
5. The system of claim 4, wherein the laser further comprises a temperature control unit electrically connected to the main controller, the temperature control unit for controlling the temperature of the laser chip; The main controller is further configured to send the control signal of the first time scale to the temperature control unit, so that the temperature control unit adjusts the temperature based on the control signal of the first time scale to perform corresponding power fluctuation compensation on the laser chip.
6. A method of multi-time scale laser power control, characterized by a master controller for use in a multi-time scale laser power control system according to any of claims 1-5, the method comprising: determining a power error signal according to the laser power signal detected by the photoelectric detector; Performing time scale division according to the power error signal to obtain a control signal of a first time scale and a control signal of a second time scale, wherein the power fluctuation bandwidth corresponding to the first time scale is lower than the power fluctuation bandwidth corresponding to the second time scale; transmitting the control signal of the first time scale to a laser, so that the laser performs corresponding power fluctuation compensation based on the control signal of the first time scale; And sending the control signal of the second time scale to an optical modulation module, so that the optical modulation module performs corresponding power fluctuation compensation based on the control signal of the second time scale.
7. The method of claim 6, wherein the light modulation module comprises at least two drive controllers and at least two acousto-optic modulators, each of the drive controllers being electrically connected to one of the acousto-optic modulators; the method further comprises the steps of: And sending the control signals of the second time scale to each driving controller, so that each driving controller sends corresponding sound wave control signals to corresponding sound wave modulators based on the control signals of the second time scale, and the sound wave modulators are used for carrying out corresponding power fluctuation compensation based on the sound wave control signals.
8. The method of claim 7, wherein the drive controller comprises a first drive controller and a second drive controller, the acousto-optic modulator comprising a first acousto-optic modulator and a second acousto-optic modulator; the method further comprises the steps of: Transmitting a control signal of a first sub-time scale to the first driving controller, so that the first driving controller transmits a first sound wave control signal to the first acousto-optic modulator based on the control signal of the first sub-time scale, and the first acousto-optic modulator is used for carrying out corresponding power fluctuation compensation based on the first sound wave control signal; And sending a control signal of a second sub-time scale to the second drive controller, so that the second drive controller sends a second sound wave control signal to the second sound modulator based on the control signal of the second sub-time scale, and the second sound modulator is used for carrying out corresponding power fluctuation compensation based on the second sound wave control signal.
9. The method of claim 6, wherein the laser comprises a laser power supply, a laser chip; the method further comprises the steps of: and sending the control signal of the first time scale to the laser power supply, so that the laser power supply adjusts output current based on the control signal of the first time scale to perform corresponding power fluctuation compensation on the laser chip.
10. The method of claim 9, wherein the laser further comprises a temperature control unit; the method further comprises the steps of: And sending the control signal of the first time scale to the temperature control unit, so that the temperature control unit adjusts the temperature based on the control signal of the first time scale to compensate the corresponding power fluctuation of the laser chip.

Description

Laser power control system and method with multiple time scales Technical Field The application relates to the field of laser technology and optical control, in particular to a laser power control system and method with multiple time scales. Background In high-end application fields such as precision optics, photoetching manufacture and the like, the stability of laser output power directly determines the core performance and working accuracy of the system. The laser is used as a key light source, the output power of the laser is easily influenced by fast time scale noise, the fast time scale noise is derived from the carrier-photon dynamic process (such as relaxation oscillation) in the laser, the noise of a driving power supply and the like, so that the power can rapidly fluctuate in a frequency range from kHz to MHz or even higher, and the application effect of the laser in a high-precision scene is severely restricted. To solve the above-mentioned problems, various laser power stabilization schemes have been proposed in the prior art, in which feedback modulation of output optical power by using a single acousto-Optic Modulator (AOM) or Electro-Optic Modulator (EOM) is a widely used technical scheme. The scheme acquires laser output power signals in real time, compares the laser output power signals with target power to obtain error signals, and adjusts working parameters of a modulator based on the error signals so as to compensate power fluctuation, thereby realizing stable control of the output power. However, the feedback modulation scheme based on the single modulator has inherent technical defects that the physical characteristics of the acousto-optic modulator and the electro-optic modulator determine the relationship between the modulation dynamic range and the response speed. If the modulator is optimized to adapt to the high-frequency noise suppression requirement with the response speed being improved, the modulation dynamic range is reduced, and the slow time scale power drift with larger amplitude is difficult to compensate. The contradiction of the characteristics makes a single modulator scheme incapable of meeting the power stability requirement in a wide time scale, so that the control bandwidth of the system is limited, full-frequency band power fluctuation from direct current to high frequency is difficult to cover, the power stability precision is reduced due to untimely compensation or insufficient compensation amplitude, the stability and reliability of the whole laser application system are finally influenced, and the severe requirement of high-end precise optical application on laser power stability cannot be met. Therefore, developing a technical scheme capable of breaking through the performance constraint of a single modulator, combining a large dynamic range and high response speed, and realizing stable laser power with wide time scale and high bandwidth becomes a technical problem to be solved in the field. Disclosure of Invention The present application is directed to the above-mentioned shortcomings in the prior art, and provides a system and a method for controlling laser power with multiple time scales, so as to solve the problems in the prior art. The technical scheme adopted by the embodiment of the application is as follows: In a first aspect, an embodiment of the present application provides a multi-time scale laser power control system, including a laser, a main controller, an optical modulation module, a beam splitter, and a photodetector; The light modulation module is arranged on a transmission light path between the light emitting surface of the laser and the light entering surface of the light splitting sheet, the first light emitting surface of the light splitting sheet faces towards the detection end of the photoelectric detector, and the second light emitting surface of the light splitting sheet is used for outputting laser signals; The main controller is used for determining a power error signal according to the laser power signal detected by the photoelectric detector, and performing time scale division according to the power error signal to obtain a first time scale control signal and a second time scale control signal, wherein the power fluctuation bandwidth corresponding to the first time scale is lower than the power fluctuation bandwidth corresponding to the second time scale; The main controller is further used for sending the control signal of the first time scale to the laser, so that the laser performs corresponding power fluctuation compensation based on the control signal of the first time scale; The main controller is further configured to send the control signal of the second time scale to the optical modulation module, so that the optical modulation module performs corresponding power fluctuation compensation based on the control signal of the second time scale. In one embodiment, the light modulation module comprises at least two drive contr