Laser beam stabilizing system and stabilizing method

Abstract

The invention discloses a laser beam stabilizing system which comprises a first spectroscope, a first fast reflecting mirror and a second fast reflecting mirror are arranged on the two opposite sides of the first spectroscope respectively, a laser transmitter is arranged on one side of the first fast reflecting mirror, and a first position sensitive detector is further arranged on one side of the first spectroscope. The first position sensitive detector is connected with a digital control system, a second spectroscope is arranged on one side of the second fast reflector, a lens is arranged on the side, away from the second fast reflector, of the second spectroscope, and a second position sensitive detector is arranged on one side of the second spectroscope. And the second position sensitive detector, the first fast reflecting mirror and the second fast reflecting mirror are all connected with the digital control system. The invention further discloses a stabilizing method of the laser beam stabilizing system. The reflecting mirror and the position sensitive detector serve as main elements, the lens and the spectroscope serve as auxiliary elements, the deflection angles of the FSM1 and the FSM2 are adjusted, the lens is used for enhancing light beams, and stable output of laser beams is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of integrated optoelectronic systems, and in particular relates to a laser beam stabilization system and also to a stabilization method of the system. Background Art

[0002] Lasers have the advantages of high brightness, monochromaticity, coherence and non-contact processing. Laser-based optical systems have been widely used in military and industrial fields. The pointing stability of the laser beam is a key factor in ensuring system performance and accuracy, and directly affects the resolution, precision and reliability of the system. However, due to environmental vibrations, thermal effects, mechanical errors and other external interferences, the pointing of the laser beam is prone to deviation and jitter, resulting in a decrease in system performance.

[0003] With the development of technology, active stabilization systems usually use a beam position adjustment system consisting of a detector and two reflectors to achieve dynamic adjustment of the laser beam direction through real-time monitoring and feedback control. However, the existing stabilization system has the problem of insufficient response speed. Summary of the invention

[0004] The object of the present invention is to provide a laser beam stabilization system capable of achieving rapid and stable output of the laser beam.

[0005] Another object of the present invention is to provide a stabilization method for a laser beam stabilization system.

[0006] The technical solution adopted by the present invention is that the laser beam stabilization system includes a first beam splitter, a first fast reflection mirror and a second fast reflection mirror are respectively arranged on two opposite sides of the first beam splitter, a laser emitter is arranged on one side of the first fast reflection mirror, a first position sensitive detector is also arranged on one side of the first beam splitter, the first position sensitive detector is connected to a digital control system, a second beam splitter is arranged on one side of the second fast reflection mirror, a lens is arranged on the side of the second beam splitter away from the second fast reflection mirror, a second position sensitive detector is arranged on one side of the second beam splitter, and the second position sensitive detector, the first fast reflection mirror and the second fast reflection mirror are all connected to the digital control system.

[0007] The present invention is also characterized in that:

[0008] The first fast reflection mirror and the second fast reflection mirror are centrally symmetrically arranged with the first beam splitter as the center.

[0009] The first fast reflection mirror and the second fast reflection mirror are both S-330 Piezo Tip / Tilt Mirror piezoelectric ceramic fast deflection mirrors.

[0010] The first position sensitive detector and the second position sensitive detector are both Hamamatsu S5991-01 detectors.

[0011] The first beamsplitter and the second beamsplitter are both Thorlabs BS013 beamsplitters.

[0012] The accuracy of the first fast reflection mirror and the second fast reflection mirror is 200 nrad, the transmittance and reflectance tolerances of the first beam splitter and the second beam splitter are both 5%, and the position resolution accuracy of the first position sensitive detector and the second position sensitive detector is 1 um.

[0013] Another technical solution adopted by the present invention is a stabilization method of a laser beam stabilization system, which is specifically implemented according to the following steps:

[0014] Step 1, the light of the laser transmitter is output to the first beam splitter through the first fast reflection mirror, the light generated by the first beam splitter is received by the first position sensitive detector and generates a light spot, and the light is received by the second fast reflection mirror and reflected to the second beam splitter, the light generated by the second beam splitter is received by the second position sensitive detector and generates a light spot, and the lens receives and collects the light and emits it;

[0015] Step 2: The first position sensitive detector and the second position sensitive detector detect the position of the light spot and send the position information to the digital control system. The digital control system calculates the optimal solution for the deflection angle of the first fast reflection mirror and the second fast reflection mirror, and adjusts the deflection angle of the first fast reflection mirror and the second fast reflection mirror according to the optimal solution, so that the light spot of the first position sensitive detector and the second position sensitive detector reaches the optimal position, thereby achieving the requirement of stable output of the laser beam passing through the lens.

[0016] In step 2, when the incident laser beam is both translated and rotated, the translation amount of the beam is X1, the deflection angle of the beam is α, α1 is the angle that FSM1 needs to deflect, the displacement of the PSD1 detector target surface is X, and the displacement of the PSD2 detector target surface is X2, then:

[0017]

[0018] The distance between the light source and FSM1 is L1, the distance between FSM1 and FSM2 is L, and the distance between FSM2 and the second beam splitter (32) is L2, where X is detected by the PSD1 detector, and L1 and L can be obtained by measurement in the experiment, then:

[0019]

[0020] FSM2 and PSD2 perform angle correction on the beam after the translation correction of FSM1 and PSD1. At this time, the angle between the beam and the vertical direction is β, and the deflection angle of FSM2 is γ. According to the deflection angle of the beam is twice the mechanical rotation angle of FSM, the relationship between them is:

[0021]

[0022] The beneficial effects of the present invention are:

[0023] The laser beam stabilization system of the present invention uses a reflector and a position sensitive detector as main components, and a lens and a beam splitter as auxiliary components. The deflection angles of FSM1 and FSM2 are adjusted, and the lens is used to enhance the light beam to achieve stable output of the laser beam. The control system receives information from the position sensor by connecting the fast reflector and the position sensitive detector, and adjusts the information sent by the fast reflector through classic PID analysis and processing to ensure that the output light is fast and stable, thereby achieving real-time monitoring and adjustment of the laser beam position. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the laser beam stabilization system of the present invention.

[0025] In the figure: 1. laser transmitter, 21. first fast reflecting mirror, 22. second fast reflecting mirror, 31. first beam splitter, 32. second beam splitter, 41. first position sensitive detector, 42. second position sensitive detector, 5. digital control system, 6. lens. DETAILED DESCRIPTION

[0026] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] The present invention provides a laser beam stabilization system, such as Figure 1As shown, it includes a first beam splitter 31, and a first fast reflection mirror 21 and a second fast reflection mirror 22 are respectively arranged on two opposite sides of the first beam splitter 31, a laser emitter 1 is arranged on one side of the first fast reflection mirror 21, and a first position sensitive detector 41 is also arranged on one side of the first beam splitter 31, and the first position sensitive detector 41 is connected to a digital control system 5, a second beam splitter 32 is arranged on one side of the second fast reflection mirror 22, a lens 6 is arranged on the side of the second beam splitter 32 away from the second fast reflection mirror 22, a second position sensitive detector 42 is arranged on one side of the second beam splitter 32, and the second position sensitive detector 42, the first fast reflection mirror 21 and the second fast reflection mirror 22 are all connected to the digital control system 5. The first fast reflector 21 and the second fast reflector 22 are used to change the direction of the laser beam and quickly respond to the deviation signal detected by the system, and adjust the reflector angle in real time to ensure the stability and accuracy of the laser beam. The first position sensitive detector 41 and the second position sensitive detector 42 are used to detect the spot position and transmit the position information to the digital control system 5. The first beam splitter 31 and the second beam splitter 32 distribute the light beam to the first position sensitive detector 41 and the second position sensitive detector 42 to determine and adjust the light beam deflection angle. The digital control system 5 receives the information of the first position sensitive detector 41 and the second position sensitive detector 42, and compares it with the target light spot, and then determines the deflection angle of the first fast reflector 21 and the second fast reflector 22. The digital control system 5 executes the classic PID algorithm to obtain the optimal solution for the deflection angle of the two fast reflectors. The lens 6 focuses the light beam. The focused laser beam has a higher power density and a smaller spot size, which can improve the resolution and accuracy of the system.

[0028] Example 1

[0029] A laser beam stabilization system includes a first beam splitter 31. A first fast reflection mirror 21 and a second fast reflection mirror 22 are respectively arranged on two opposite sides of the first beam splitter 31. A laser emitter 1 is arranged on one side of the first fast reflection mirror 21. A first position sensitive detector 41 is also arranged on one side of the first beam splitter 31. The first position sensitive detector 41 is connected to a digital control system 5. A second beam splitter 32 is arranged on one side of the second fast reflection mirror 22. A lens 6 is arranged on the side of the second beam splitter 32 away from the second fast reflection mirror 22. A second position sensitive detector 42 is arranged on one side of the second beam splitter 32. The second position sensitive detector 42, the first fast reflection mirror 21 and the second fast reflection mirror 22 are all connected to the digital control system 5.

[0030] The first fast reflection mirror 21 and the second fast reflection mirror 22 are centrally symmetrically arranged around the first beam splitter 31. Two fast reflection mirrors are arranged, and are respectively located in front of the laser emitter 1 and in front of the beam splitter.

[0031] The first fast reflection mirror 21 and the second fast reflection mirror 22 are both S-330 Piezo Tip / Tilt Mirror piezoelectric ceramic fast deflection mirrors.

[0032] The first position sensitive detector 41 and the second position sensitive detector 42 are both Hamamatsu S5991-01 detectors. Two position sensitive detectors are provided, and are respectively located in front of the spectroscope.

[0033] The first beam splitter 31 and the second beam splitter 32 are both Thorlabs BS013 beam splitters.

[0034] Example 2

[0035] A laser beam stabilization system includes a first beam splitter 31. A first fast reflection mirror 21 and a second fast reflection mirror 22 are respectively arranged on two opposite sides of the first beam splitter 31. A laser emitter 1 is arranged on one side of the first fast reflection mirror 21. A first position sensitive detector 41 is also arranged on one side of the first beam splitter 31. The first position sensitive detector 41 is connected to a digital control system 5. A second beam splitter 32 is arranged on one side of the second fast reflection mirror 22. A lens 6 is arranged on the side of the second beam splitter 32 away from the second fast reflection mirror 22. A second position sensitive detector 42 is arranged on one side of the second beam splitter 32. The second position sensitive detector 42, the first fast reflection mirror 21 and the second fast reflection mirror 22 are all connected to the digital control system 5.

[0036] The accuracy of the first fast reflection mirror 21 and the second fast reflection mirror 22 is 200 nrad, the transmittance and reflectance tolerances of the first beam splitter 31 and the second beam splitter 32 are both 5%, and the position resolution accuracy of the first position sensitive detector 41 and the second position sensitive detector 42 is 1 um.

[0037] Example 3

[0038] The stabilization method of the laser beam stabilization system of the present invention is specifically implemented according to the following steps:

[0039] Step 1, the light of the laser emitter 1 is output to the first beam splitter 31 through the first fast reflection mirror 21, the light generated on the first beam splitter 31 is received by the first position sensitive detector 41 and generates a light spot, and the second fast reflection mirror 22 receives and reflects the light to the second beam splitter 32, the light generated on the second beam splitter 32 is received by the second position sensitive detector 42 and generates a light spot, and the lens 6 receives and gathers the light for emission;

[0040] Step 2, the first position sensitive detector 41 and the second position sensitive detector 42 detect the position of the light spot and send the position information to the digital control system 5, the digital control system 5 executes the classic PID algorithm to obtain the optimal solution for the deflection angle of the first fast reflection mirror 21 and the second fast reflection mirror 22, and adjusts the deflection angle of the first fast reflection mirror 21 and the second fast reflection mirror 22 according to the optimal solution, so that the light spot of the first position sensitive detector 41 and the second position sensitive detector 42 reaches the optimal position, thereby achieving the requirement of stable output of the laser beam passing through the lens 6.

[0041] The working principle of the laser beam stabilization system of the present invention is as follows:

[0042] FSM1 and FSM2 are the first fast reflection mirror 21 and the second fast reflection mirror 22, respectively. PSD1 and PSD2 are the first position sensitive detector 41 and the second position sensitive detector 42, respectively. When the incident laser beam is both translated and rotated, the translation amount of the beam is X1, the deflection angle of the beam is α, α1 is the angle that FSM1 needs to deflect, the displacement of the target surface of the PSD1 detector is X, and the displacement of the target surface of the PSD2 detector is X2, then:

[0043]

[0044] The distance between the light source and FSM1 is L1, the distance between FSM1 and FSM2 is L, and the distance between FSM2 and the second beam splitter 32 is L2, where X is detected by the PSD1 detector, and L1 and L can be obtained by measurement in the experiment. Figure 1 The geometric relations in are:

[0045]

[0046] FSM2 and PSD2 perform angle correction on the beam after the translation correction of FSM1 and PSD1. At this time, the angle between the beam and the vertical direction is β, and the deflection angle of FSM2 is γ. According to the deflection angle of the beam is twice the mechanical rotation angle of FSM, the relationship between them is:

[0047]

[0048] Reflectors and position sensitive detectors are used as main components, and lenses and beam splitters are used as auxiliary components. The deflection angles of FSM1 and FSM2 are adjusted, and the lens is used to enhance the light beam to achieve stable output of the laser beam.

[0049] The digital control system of the present invention receives information from the position sensor by connecting the fast reflector and the position sensitive detector, and adjusts the information sent by the fast reflector after analyzing and processing with the classic PID algorithm to ensure that the emitted light is fast and stable, thereby realizing real-time monitoring and adjustment of the laser beam position, so that the light spots on the two position sensitive detectors reach the optimal position, thereby meeting the requirement of stable laser beam output.

Claims

1. Laser beam stabilization system, characterized in that, The invention comprises a first beam splitter (31), wherein a first fast reflection mirror (21) and a second fast reflection mirror (22) are respectively arranged on two opposite sides of the first beam splitter (31), a laser emitter (1) is arranged on one side of the first fast reflection mirror (21), a first position sensitive detector (41) is also arranged on one side of the first beam splitter (31), the first position sensitive detector (41) is connected to a digital control system (5), a second beam splitter (32) is arranged on one side of the second fast reflection mirror (22), a lens (6) is arranged on the side of the second beam splitter (32) away from the second fast reflection mirror (22), a second position sensitive detector (42) is arranged on one side of the second beam splitter (32), and the second position sensitive detector (42), the first fast reflection mirror (21) and the second fast reflection mirror (22) are all connected to the digital control system (5).

2. The laser beam stabilization system according to claim 1, characterized in that: The first fast reflection mirror (21) and the second fast reflection mirror (22) are arranged in a centrally symmetrical manner with the first beam splitter (31) as the center.

3. The laser beam stabilization system according to claim 1, characterized in that: The first fast reflection mirror (21) and the second fast reflection mirror (22) are both S-330 Piezo Tip / Tilt Mirror piezoelectric ceramic fast deflection mirrors.

4. The laser beam stabilization system according to claim 1, characterized in that: The first position sensitive detector (41) and the second position sensitive detector (42) are both Hamamatsu S5991-01 detectors.

5. The laser beam stabilization system according to claim 1, characterized in that: The first beam splitter (31) and the second beam splitter (32) are both Thorlabs BS013 beam splitters.

6. The laser beam stabilization system according to claim 1, characterized in that: The accuracy of the first fast reflection mirror (21) and the second fast reflection mirror (22) is 200 nrad, the transmittance and reflectance tolerances of the first beam splitter (31) and the second beam splitter (32) are both 5%, and the position resolution accuracy of the first position sensitive detector (41) and the second position sensitive detector (42) is 1 um.

7. The stabilization method of a laser beam stabilization system according to any one of claims 1 to 6, characterized in that: Follow the steps below to implement it: Step 1, the light of the laser emitter (1) is output to the first beam splitter (31) through the first fast reflection mirror (21), the light generated on the first beam splitter (31) is respectively received by the first position sensitive detector (41) and generates a light spot, and the light is received by the second fast reflection mirror (22) and reflected to the second beam splitter (32), the light generated on the second beam splitter (32) is respectively received by the second position sensitive detector (42) and generates a light spot, and the lens (6) receives and gathers the light and emits it; Step 2: The first position sensitive detector (41) and the second position sensitive detector (42) detect the position of the light spot and send the position information to the digital control system (5); the digital control system (5) calculates the optimal solution for the deflection angle of the first fast reflection mirror (21) and the second fast reflection mirror (22); and adjusts the deflection angle of the first fast reflection mirror (21) and the second fast reflection mirror (22) according to the optimal solution, so that the light spot of the first position sensitive detector (41) and the second position sensitive detector (42) reaches the optimal position, thereby meeting the requirement of stable output of the laser beam passing through the lens (6).

8. The stabilization method of the laser beam stabilization system according to claim 7, characterized in that: In step 2, when the incident laser beam is both translated and rotated, the translation amount of the beam is X1, the deflection angle of the beam is α, α1 is the angle that FSM1 needs to deflect, the displacement of the PSD1 detector target surface is X, and the displacement of the PSD2 detector target surface is X2, then: The distance between the light source and FSM1 is L1, the distance between FSM1 and FSM2 is L, and the distance between FSM2 and the second beam splitter (32) is L2, where X is detected by the PSD1 detector, and L1 and L can be obtained by measurement in the experiment, then: FSM2 and PSD2 perform angle correction on the beam after the translation correction of FSM1 and PSD1. At this time, the angle between the beam and the vertical direction is β, and the deflection angle of FSM2 is γ. According to the deflection angle of the beam is twice the mechanical rotation angle of FSM, the relationship between them is:

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