Grating adjusting device, laser adjusting system and laser

Abstract

The utility model provides a grating adjusting device, a laser adjusting system and a laser, comprising an angle adjusting plate, a static grating frame, a moving grating frame, a static grating and a moving grating, the static grating is installed on the static grating frame, the moving grating is installed on the moving grating frame, the static grating frame is installed on the angle adjusting plate, and the moving grating is installed on the angle adjusting plate. And the movable grating frame is connected with the angle adjusting plate in a sliding manner. According to the utility model, the problem that the pulse dispersion variation precision of the existing stretcher or compressor cannot be adjusted can be solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of laser broadening and compression technology, especially to a grating adjusting device, a laser adjusting system and a laser. BACKGROUND

[0002] Femtosecond high peak power density (TW / cm2) and high repetition frequency (MHz) laser systems are widely used in scientific, industrial and military fields. The main mechanism of controlling femtosecond pulse and material interaction is multi-photon phenomenon and non-thermal process, which makes them have unique attraction for various applications. At present, femtosecond lasers show excellent ability in three-dimensional machining of transparent materials (such as fused quartz, sapphire, etc.), and become excellent tools for fiber micro-machining (such as fiber grating writing), semiconductor wafer cutting, rewritable 5D optical memory. In addition, femtosecond laser can change the surface of solar panel to improve the efficiency of solar cell. People are moving towards ultrafast lasers with higher power, larger pulse energy and narrower pulse width. In the amplifier of ultra-short pulse, the peak intensity of light will become very high, so that nonlinear pulse distortion of pulse may occur, and even damage to the gain medium and other elements may occur. In this case, Chirped-pulse Amplification (CPA) can well avoid the above problems. Chirped-pulse Amplification is to use a stretcher (chirped grating, long fiber) to stretch in time domain before amplification, so as to reduce the peak power of pulse, and then amplify. After amplification, a compressor (grating) is used to compensate the dispersion and compress the pulse width. The compressor has opposite dispersion to the stretcher. Therefore, high-power, large-energy and narrow-pulse-width ultra-short pulse output can be finally obtained.

[0003] However, the current stretcher mainly uses chirped fiber grating. In order to obtain high-energy and high-peak-power ultrafast pulse output without nonlinearity in chirped pulse amplification, the stretching amount and dispersion management are very important. Large stretching amount can reduce nonlinearity to a greater extent, so as to obtain higher energy amplification. However, the dispersion amount of chirped fiber grating is limited. The invention patent (CN109407354A) "Transmission type single grating multi-pass tunable pulse stretching device" proposes to use single grating multiple passes for pulse stretching. However, the pulse dispersion change amount of this device is not convenient to adjust.

[0004] Therefore, it is necessary to provide a grating adjusting device, a laser adjusting system and a laser, so that the pulse dispersion change amount precision of the existing stretcher or compressor can be adjusted. Utility model content

[0005] The utility model discloses a grating adjusting device, laser adjusting system and laser, to solve the precision of the pulse dispersion variation of the existing spreader or compressor is not adjustable.

[0006] To solve the above technical problems, the utility model provides a grating adjusting device, including angle adjusting board, static grating frame, dynamic grating frame, static grating, dynamic grating, static grating is installed on static grating frame, dynamic grating is installed on dynamic grating frame, static grating frame is installed on angle adjusting board, dynamic grating frame with angle adjusting board sliding connection.

[0007] Optionally, the static grating and the dynamic grating form a parallelogram first pair of sides or are respectively isosceles trapezoidal two waist.

[0008] Optionally, the dynamic grating frame sliding direction is parallel with the second pair of sides of the parallelogram or parallel with the upper base of the isosceles trapezoid.

[0009] Optionally, the dynamic grating frame includes a sliding block and a bracket arranged on the sliding block, the dynamic grating is arranged on the bracket, a group of first sliding grooves are arranged on the angle adjusting plate, a group of first rollers are arranged on the sliding block, and the first rollers are in sliding fit with the first sliding grooves.

[0010] Optionally, the grating adjusting device further includes a base, and the angle adjusting plate is rotationally connected with the base.

[0011] The utility model also provides a laser adjusting system, including incident light path device, emergent light path device and above-mentioned grating adjusting device, grating adjusting device is located on the emergent light path of incident light path device, and emergent light path device is located on the emergent light path of grating adjusting device.

[0012] Optionally, it further includes a light path driving device for driving laser to and fro penetration grating adjusting device, the light path driving device is located on the emergent light path of incident light path device, and the emergent light path is located on the emergent light path of light path driving device.

[0013] Optionally, the light path driving device comprises a first polarization beam splitting prism, a first half-wave plate, an electro-optical modulator, a second polarization beam splitting prism, a first zero-degree mirror, a second half-wave plate and a second zero-degree mirror, the first polarization beam splitting prism is located on an exit light path of the incident light path device, the first half-wave plate, the electro-optical modulator, the second polarization beam splitting prism and the first zero-degree mirror are sequentially located on a reflection light path of the first polarization beam splitting prism, the second polarization beam splitting prism, the electro-optical modulator, the first half-wave plate, the first polarization beam splitting prism, the second half-wave plate, the grating adjusting device and the second zero-degree mirror are sequentially located on a reflection light path of the first zero-degree mirror, and the exit light path device is located on a reflection light path of the second polarization beam splitting prism.

[0014] Optionally, the incident light path device comprises a lens group for collimating the laser before the laser enters the first polarization beam splitting prism.

[0015] The utility model also provides a kind of laser, including laser excitation system and above-mentioned laser adjusting system, the laser adjusting system is emitted to the laser of laser excitation system and is spread or compressed.

[0016] The utility model provides a kind of grating adjusting device, laser adjusting system and laser, with following

[0017] Beneficial effects:

[0018] Since the moving grating is installed on the moving grating frame, the static grating is installed on the static grating frame, and the moving grating frame is slidably connected with the angle adjusting plate, therefore, the moving grating can slide relative to the static grating, that is, the distance between the moving grating and the static grating is adjustable, so that the dispersion variation precision of the laser passing through the grating adjusting device can be adjusted. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the structure diagram of grating adjusting device in the utility model embodiment;

[0020] Figure 2 is the top view of grating adjusting device in the utility model embodiment;

[0021] Figure 3 is the light path principle diagram of laser adjusting system in the utility model embodiment;

[0022] Figure 4 is the schematic diagram of polarization state variation of laser of laser adjusting system in the utility model embodiment (point indicates vertical polarization, arrow indicates horizontal polarization);

[0023] Figure 5is a timing sequence and laser pulse broadening compression dispersion change schematic diagram of an electro-optical modulator of a laser adjusting system in the embodiment of the utility model.

[0024] Reference signs:

[0025] 100-grating adjusting device;110-angle adjusting plate;111-first sliding groove;112-first scale;113-second sliding groove;120-sliding block;121-first roller;130-static grating frame;140-dynamic grating frame;150-static grating;160-dynamic grating;170-base;171-second roller;172-second scale;211-first polarizing beam splitter prism;212-first half wave plate;213-electro-optical modulator;214-second polarizing beam splitter prism;215-first zero-degree mirror;216-second half wave plate;217-second zero-degree mirror;218-concave lens;219-convex lens;220-space light isolator;221-third half wave plate. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. The components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0027] Therefore, the detailed description of the embodiments of the utility model provided in the drawings below is not intended to limit the scope of the claimed utility model, but only represents selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the utility model.

[0028] It should be noted that: similar signs and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0029] In the description of the utility model, it needs to explain, the term "center", "upper", "lower", "left", "right", "vertical", "horizontal", "internal", "external" and so on indicate the orientation or position relation is based on the orientation or position relation shown in the drawing, or it is the orientation or position relation of the utility model product when using usually, only for the convenience of describing the utility model and simplifying the description, and cannot indicate or imply that the indicated device or element must have a particular orientation, construct and operate, therefore cannot be understood as the limitation of the utility model. In addition, the term "first", "second", "third" and so on are only used for distinguishing description, and cannot be understood as indicating or implying relative importance.

[0030] In addition, the terms "horizontal", "vertical" and other terms do not mean that the component is absolutely horizontal or overhanging, but can be slightly inclined. As "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0031] In the description of the utility model, it also needs to explain that, unless otherwise expressly provided and limited, the terms "set", "install", "connect", "connect" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected, can be mechanically connected, can be electrically connected, can be directly connected, or indirectly connected through an intermediate medium, can be the connection between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0032] Reference Figure 1 And Figure 2 , Figure 1 It is the structure diagram of grating adjusting device 100 in the utility model embodiment, Figure 2 It is the top view of grating adjusting device 100 in the utility model embodiment, the utility model provides a kind of grating adjusting device 100, including angle adjusting plate 110, static grating frame 130, dynamic grating frame 140, static grating 150, dynamic grating 160, the static grating 150 is installed on the static grating frame 130, the dynamic grating 160 is installed on the dynamic grating frame 140, the static grating frame 130 is installed on the angle adjusting plate 110, the dynamic grating frame 140 is slidably connected with the angle adjusting plate 110. Since the dynamic grating 160 is installed on the dynamic grating frame 140, the static grating 150 is installed on the static grating frame 130, the dynamic grating frame 140 is slidably connected with the angle adjusting plate 110, therefore, the dynamic grating 160 can slide relative to the static grating 150, i.e. the interval between the dynamic grating 160 and the static grating 150 is adjustable, so that the precision of the dispersion variation of laser passing through grating adjusting device 100 can be adjusted.

[0033] The static grating 150 and the dynamic grating 160 form a first pair of opposite sides of a parallelogram or two legs of an isosceles trapezoid, respectively. Since the static grating 150 and the dynamic grating 160 form a first pair of opposite sides of a parallelogram or two legs of an isosceles trapezoid, respectively, when the static grating 150 and the dynamic grating 160 form a first pair of opposite sides of a parallelogram, the laser pulse passing through the static grating 150 and the dynamic grating 160 can be negatively dispersed, thereby achieving compression, and when the static grating 150 and the dynamic grating 160 are two legs of an isosceles trapezoid, the laser pulse passing through the static grating 150 and the dynamic grating 160 can be positively dispersed, thereby achieving expansion. In this way, the grating adjusting device 100 can be used for both an expander and a compressor, and is suitable for two types of grating pairs, which can expand the range of use.

[0034] Further, the sliding direction of the dynamic grating frame 140 is parallel to a second pair of opposite sides of the parallelogram or parallel to the upper base of the isosceles trapezoid. In this way, when adjusting the distance between the dynamic grating 160 and the static grating 150, only the distance between the dynamic grating 160 and the static grating 150 can be changed, without changing the relative area of the dynamic grating 160 and the static grating 150, which can further improve the precision of the change in the dispersion of the laser.

[0035] Specifically, the dynamic grating frame 140 includes a sliding block 120 and a bracket provided on the sliding block 120, and the dynamic grating 160 is provided on the bracket. A first sliding groove 111 is provided on the angle adjusting plate 110, and a first roller 121 is provided on the sliding block 120, and the first roller 121 is in sliding fit with the first sliding groove 111.

[0036] A first scale 112 is provided on the angle adjusting plate 110, which can facilitate the adjustment of the position of the dynamic grating frame 140.

[0037] Specifically, the first roller 121 is a shoulder screw.

[0038] Preferably, the sliding plate is an isosceles triangle.

[0039] The grating adjusting device 100 further includes a base 170, and the angle adjusting plate 110 is rotationally connected to the base 170. In this way, the incident angle of the laser relative to the static grating 150 and the dynamic grating 160 can be adjusted.

[0040] Further, the angle adjusting plate 110 is provided with a second sliding groove 113, and the base 170 is provided with a second roller 171, which is in sliding connection with the second sliding groove 113, so that the rotation accuracy of the angle adjusting plate 110 relative to the base 170 is improved, thereby improving the adjustment accuracy.

[0041] The base 170 is provided with a second scale 172, so that the position of the angle adjusting plate 110 can be adjusted, thereby facilitating the adjustment of the incident angle of the laser relative to the static grating 150 and the dynamic grating 160.

[0042] The second roller 171 is preferably a shoulder screw.

[0043] Reference Figure 3 、 Figure 4 and Figure 5 , Figure 3 is a light path principle diagram of the laser adjusting system in the embodiment of the utility model, Figure 4 is a schematic diagram of polarization state change of laser of the laser adjusting system in the embodiment of the utility model (point represents vertical polarization, arrow represents horizontal polarization), Figure 5 is a schematic diagram of laser pulse expansion compression dispersion change of electro-optical modulator time sequence of the laser adjusting system in the embodiment of the utility model, and the embodiment further provides a laser adjusting system, which comprises an incident light path device, an emergent light path device and the above-mentioned grating adjusting device 100, the grating adjusting device 100 is located on the emergent light path of the incident light path device, and the emergent light path device is located on the emergent light path of the grating adjusting device 100.

[0044] The laser adjusting system further comprises a light path driving device for driving laser to penetrate the grating adjusting device 100 back and forth, the light path driving device is located on the emergent light path of the incident light path device, and the emergent light path is located on the emergent light path of the light path driving device.

[0045] The light path driving device comprises a first polarization beam splitting prism 211, a first half wave plate 212, an electro-optical modulator 213, a second polarization beam splitting prism 214, a first zero-degree mirror 215, a second half wave plate 216 and a second zero-degree mirror 217, the first polarization beam splitting prism 211 is located on the exit light path of the incident light path device, the first half wave plate 212, the electro-optical modulator 213, the second polarization beam splitting prism 214 and the first zero-degree mirror 215 are sequentially located on the reflected light path of the first polarization beam splitting prism 211, the second polarization beam splitting prism 214, the electro-optical modulator 213, the first half wave plate 212, the first polarization beam splitting prism 211, the second half wave plate 216, the grating adjusting device 100 and the second zero-degree mirror 217 are sequentially located on the reflected light path of the first zero-degree mirror 215, and the exit light path device is located on the reflected light path of the second polarization beam splitting prism 214.

[0046] The laser emitted from the exit of the incident light path device is reflected by the first polarization beam splitting prism 211, sequentially passes through the first half wave plate 212, the electro-optical modulator 213 for laser passing and the second polarization beam splitting prism 214, is transmitted by the second polarization beam splitting prism 214 and enters the first zero-degree mirror 215, is reflected by the first zero-degree mirror 215, is transmitted by the second polarization beam splitting prism 214, enters the electro-optical modulator 213 for changing the polarization direction of laser, then passes through the first half wave plate 212, is transmitted by the first polarization beam splitting prism 211 and enters the second half wave plate 216, then passes through the grating adjusting device 100 and enters the second zero-degree mirror 217, is reflected by the second zero-degree mirror 217, sequentially passes through the grating adjusting device 100, the second half wave plate 216, the first polarization beam splitting prism 211, the first half wave plate 212, the electro-optical modulator 213 for changing the polarization state of laser, the second polarization beam splitting prism 214 and the first zero-degree mirror 215, then the laser is reflected back and forth between the first zero-degree mirror and the second zero-degree mirror, when the laser is reflected from the second zero-degree mirror 217 to the first zero-degree mirror, after passing through the electro-optical modulator 213 for laser passing, the laser is reflected by the second polarization beam splitting prism 214 and is outputted.

[0047] Thus, by changing the state of the electro-optical modulator 213, when the electro-optical modulator 213 allows the laser to pass, the polarization state of the laser is not changed; when the electro-optical modulator 213 changes the polarization state of the laser, the electro-optical modulator 213 changes the vertical polarization laser to horizontal polarization laser or changes the horizontal polarization laser to vertical polarization laser, so that the electro-optical modulator 213 changes the polarization state of the laser to make the laser reflect back and forth between the first zero-degree mirror 215 and the second zero-degree mirror 217, or the electro-optical modulator 213 allows the laser to pass, so that the laser is reflected from the second polarization beam splitter prism 214 and output, so that the laser can be output after reflecting back and forth between the first zero-degree mirror 215 and the second zero-degree mirror 217 N times. Correspondingly, the laser can be time-domain stretched or compressed for 2N times with a certain dispersion compensation amount. Thus, by controlling the number of times of laser stretching or compression and the size of single dispersion compensation amount, the pulse time-domain width of the laser signal can be accurately controlled. A wider stretching amount can well avoid nonlinearity to obtain higher power and larger energy amplification, and fine adjustment and management of dispersion can make the quality of the amplified pulse better.

[0048] Specifically, the vertical polarized laser is reflected into the first half-wave plate 212 after the first polarizing beam splitter prism 211 to become horizontal polarized laser, then enters the second polarizing beam splitter prism 214 after the closed electro-optical modulator 213, is transmitted through the second polarizing beam splitter prism 214 to enter the first zero-degree mirror 215, is reflected by the first zero-degree mirror 215 to enter the second polarizing beam splitter prism 214, is transmitted through the second polarizing beam splitter prism 214 to enter the opened electro-optical modulator 213, becomes vertical polarized laser after the electro-optical modulator 213, becomes horizontal polarized laser after the first half-wave plate 212, is transmitted through the first polarizing beam splitter prism 211 to enter the second half-wave plate 216, becomes vertical polarized laser after the second half-wave plate 216, is transmitted through the grating adjusting device 100 to the second zero-degree mirror 217, is reflected by the second zero-degree mirror 217 to enter the grating adjusting device 100, then becomes vertical polarized laser after the second half-wave plate 216, becomes horizontal polarized laser, is transmitted through the first polarizing beam splitter prism 211 to enter the first half-wave plate 212 to become vertical polarized laser, becomes horizontal polarized laser after the electro-optical modulator 213, is transmitted through the second polarizing beam splitter prism 214 to enter the first zero-degree mirror 215, is reflected by the first zero-degree mirror 215 to be transmitted through the second polarizing beam splitter prism 214 to enter the electro-optical modulator 213, becomes vertical polarized laser after the electro-optical modulator 213, then becomes horizontal polarized laser after the first half-wave plate 212, is transmitted through the first polarizing beam splitter prism 211 to enter the second half-wave plate 216 to become vertical polarized laser, is transmitted through the grating adjusting device 100 to the second zero-degree mirror 217, then the laser is reflected back and forth between the first zero-degree mirror 215 and the second zero-degree mirror 217, when the laser is reflected from the second zero-degree mirror 217 to the first zero-degree mirror 215 and passes through the electro-optical modulator 213, the electro-optical modulator 213 is closed only for the laser to pass through, then the laser enters the second polarizing beam splitter prism 214 again, and is reflected by the second polarizing beam splitter prism 214 to be output.

[0049] Preferably, the incident light path device further comprises a lens group for collimating the laser before the laser enters the first polarizing beam splitter prism 211. In this embodiment, the lens group comprises a concave lens 218 and a convex lens 219, and the laser enters the first polarizing beam splitter prism 211 after sequentially passing through the concave lens 218 and the convex lens 219.

[0050] Preferably, the incident light path device further comprises a spatial light isolator 220 before the laser enters the first polarizing beam splitter prism 211.

[0051] Preferably, the incident light path device further comprises a third quarter wave plate 221 which does not change the polarization direction of the laser before the laser enters the first polarization beam splitting prism 211, so that the polarization performance of the laser entering the first polarization beam splitting prism 211 is better.

[0052] Further, the third quarter wave plate 221 is arranged between the lens group and the first polarization beam splitting prism.

[0053] The embodiment also provides a laser device, which comprises a laser excitation system and the laser adjustment system in the above embodiment, and the laser adjustment system is used for expanding or compressing the laser emitted by the laser excitation system.

[0054] In the embodiment, the incident light axis of the first zero-degree mirror is coaxial with the outgoing light axis, and the incident light axis of the second zero-degree mirror is coaxial with the outgoing light axis.

[0055] The above description is only a description of the preferred embodiment of the utility model, and does not limit the scope of the utility model, and any change or modification of the above disclosure by the ordinary skilled in the art belongs to the protection scope of the claims.

Claims

1. A grating adjustment device, characterized in that, It includes an angle adjustment plate, a static grating frame, a moving grating frame, a static grating, and a moving grating. The static grating is mounted on the static grating frame, the moving grating is mounted on the moving grating frame, and the static grating frame is mounted on the angle adjustment plate. The moving grating frame is slidably connected to the angle adjustment plate.

2. The grating adjustment device as described in claim 1, characterized in that, The static grating and the dynamic grating respectively form the first pair of opposite sides of a parallelogram or the two legs of an isosceles trapezoid.

3. The grating adjustment device as described in claim 2, characterized in that, The sliding direction of the moving grating frame is parallel to the second set of opposite sides of the parallelogram or parallel to the upper base of the isosceles trapezoid.

4. The grating adjustment device as described in claim 1, characterized in that, The moving grating frame includes a slider and a bracket disposed on the slider. The moving grating is disposed on the bracket. A set of first sliding grooves is provided on the angle adjustment plate. A set of first rollers is provided on the slider. The first rollers slide in cooperation with the first sliding grooves.

5. The grating adjustment device as described in claim 1, characterized in that, The grating adjustment device also includes a base, and the angle adjustment plate is rotatably connected to the base.

6. A laser modulation system, characterized in that, It includes an incident optical path device, an exit optical path device, and a grating adjustment device as described in any one of claims 1 to 5, wherein the grating adjustment device is located on the exit optical path of the incident optical path device, and the exit optical path device is located on the exit optical path of the grating adjustment device.

7. The laser modulation system as described in claim 6, characterized in that, It also includes an optical path driving device for driving the laser to travel back and forth through the grating adjustment device, the optical path driving device being located on the outgoing optical path of the incident optical path device, and the outgoing optical path being located on the outgoing optical path of the optical path driving device.

8. The laser modulation system as described in claim 7, characterized in that, The optical path driving device includes a first polarizing beam splitter prism, a first half-wave plate, an electro-optic modulator, a second polarizing beam splitter prism, a first zero-degree reflector, a second half-wave plate, and a second zero-degree reflector. The first polarizing beam splitter prism is located on the outgoing optical path of the incident optical path device. The first half-wave plate, the electro-optic modulator, the second polarizing beam splitter prism, and the first zero-degree reflector are sequentially located on the reflected optical path of the first polarizing beam splitter prism. The second polarizing beam splitter prism, the electro-optic modulator, the first half-wave plate, the first polarizing beam splitter prism, the second half-wave plate, the grating adjustment device, and the second zero-degree reflector are sequentially located on the reflected optical path of the first zero-degree reflector. The outgoing optical path device is located on the reflected optical path of the second polarizing beam splitter prism.

9. The laser modulation system as described in claim 8, characterized in that, The incident optical path device includes a lens group that collimates the laser beam before it enters the first polarizing beam splitter.

10. A laser, characterized in that, It includes a laser excitation system and a laser modulation system as described in any one of claims 6-9, wherein the laser modulation system broadens or compresses the laser emitted by the laser excitation system.

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