Chirped pulse compressor without changing morphology of input light spot

Abstract

The utility model discloses a chirped pulse compressor without changing the shape of an input light spot. The chirped pulse compressor comprises two diffraction gratings which are parallel to each other and a light path vertical lifter, the two diffraction gratings are respectively a diffraction grating A and a diffraction grating B; after incident light enters the diffraction grating A, the incident light is diffracted to the diffraction grating B; the diffracted light beam is diffracted by the diffraction grating B and then enters the light path vertical lifter, and the light path vertical lifter enables the emergent light of the diffraction grating B to change the height and then return in parallel to the original light path at different heights. According to the utility model, the two reflectors are utilized to form a light path vertical lifter, so that the shape and polarization of an input pulse light spot do not change at all after passing through the compressor.

Description

Technical Field

[0001] The utility model relates to the technical field of optics, in particular to a chirped pulse compressor which does not change the input light spot morphology. Background Art

[0002] At present, chirped pulse amplification technology stretches the laser pulse in time, amplifies it, and then re-compresses it into a short pulse. When the pulse is stretched, the peak power will drop significantly, so that the laser pulse energy can be amplified to a larger multiple without damaging the amplifier. After that, the pulse is re-compressed, so that the pulse time width is restored to a value similar to the incident pulse.

[0003] Pulse stretchers and compressors usually contain grating devices (or pulse stretchers and compressors are a special optical path containing gratings). Pulse stretchers generally use one grating, and compressors generally use two gratings. The gratings can be transmission gratings. The diffraction effect of the grating on light is used to produce dispersion. The stretcher generally provides positive dispersion, so that the laser pulse is stretched in the time domain. The compressor generally provides negative dispersion opposite to the stretcher, so that the amplified laser pulse is compressed back to a near initial pulse width in the time domain. Femtosecond pulse chirp amplifiers with high pulse energy and high peak power have very important applications in fields such as industrial precision machining. The main principle is to stretch the femtosecond seed source to hundreds of picoseconds or even nanoseconds through a stretcher, and then amplify it. Finally, the compressor is used to compress the output pulse width back to the femtosecond level, so as to achieve high pulse energy and high peak power femtosecond pulse laser output.

[0004] After being compressed, the pulse incident on the stretcher will return to the original path at different heights and be led out to the output end by the reflector. The pulse compressor in the femtosecond pulse laser in the prior art is realized by a pair of diffraction gratings. The main reason for the decline in the quality of the pulse spot after passing through the compressor is the use of a highly inclined optical path design, which seriously affects the quality of the output spot of the pulse compressor. Utility Model Content

[0005] The utility model provides a chirped pulse compressor which does not change the input light spot morphology in order to solve the technical problems existing in the known technology.

[0006] The technical solution adopted by the utility model to solve the technical problems existing in the known technology is:

[0007] A chirped pulse compressor that does not change the input light spot shape includes two mutually parallel diffraction gratings and an optical path vertical lifter; the two diffraction gratings are: diffraction grating A and diffraction grating B; after the incident light is incident on the diffraction grating A, it is diffracted to the diffraction grating B; the diffracted light beam is diffracted by the diffraction grating B and then incident on the optical path vertical lifter, and the optical path vertical lifter changes the height of the outgoing light of the diffraction grating B and returns at different heights parallel to the original optical path.

[0008] Furthermore, the optical path vertical lifter includes two mutually perpendicular mirrors, which are reflector A and reflector B respectively; reflector B is located below reflector A; the light beam from the diffraction grating B is incident on reflector A or reflector B, and when the light beam is horizontally incident on reflector A, the light beam is reflected by reflector A and then vertically incident on reflector B downward, and is output horizontally after being reflected by reflector B; when the light beam is horizontally incident on reflector B, the light beam is reflected by reflector B and then vertically incident on reflector A upward, and is output horizontally after being reflected by reflector A.

[0009] Furthermore, the vertical distance between the centers of the reflector A and the reflector B is adjustable.

[0010] The advantages and positive effects of the utility model are: for the usual inclined optical path design, two reflectors are used to form an optical path vertical lifter, which will make the input pulse spot morphology and polarization completely unchanged after passing through the compressor. This design is very easy to improve on the basis of the existing compressor design and has excellent use effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of a pulse compressor in the prior art.

[0012] Figure 2 The utility model is a schematic diagram of the structure of an optical path vertical lifter.

[0013] In the figure: 1. Diffraction grating A; 2. Diffraction grating B; 3. Reflector; 4. Light path vertical lifter; 5. Reflector A; 6. Reflector B. DETAILED DESCRIPTION

[0014] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0015] In the description of the present invention, the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0016] See also Figure 1 An existing pulse compressor is implemented by using a pair of diffraction gratings. The incident light passes through the pair of diffraction gratings and then reflects through a reflector 3 and returns to the grating at different heights. This method will elongate the light spot and the polarization will also have a small change. Figure 1 It is a schematic diagram of the projection of various components and optical paths on the XY plane in the three-dimensional XYZ coordinate system.

[0017] See also Figure 2 A chirped pulse compressor that does not change the input light spot shape, characterized in that it includes two mutually parallel diffraction gratings and an optical path vertical lifter; the two diffraction gratings are: diffraction grating A1 and diffraction grating B2; after the incident light is incident on the diffraction grating A1, it is diffracted to the diffraction grating B2; the diffracted light beam is diffracted by the diffraction grating B2 and then incident on the optical path vertical lifter 4, and the optical path vertical lifter 4 changes the height of the output light of the diffraction grating B2 and returns at different heights parallel to the original optical path. Figure 2 It is a schematic diagram of the projection of various components and optical paths on the XZ plane in the three-dimensional XYZ coordinate system.

[0018] Preferably, the optical path vertical lifter 4 may include two mutually perpendicular reflectors, which may be reflector A5 and reflector B6 respectively; reflector B6 may be located below reflector A5; the light beam from the diffraction grating B2 is incident on reflector A5 or reflector B6, and when the light beam from the diffraction grating B2 is horizontally incident on reflector A5, the light beam is reflected by reflector A5 and then vertically incident on reflector B6, and then is reflected by reflector B6 and then is output horizontally; when the light beam from the diffraction grating B2 is horizontally incident on reflector B6, the light beam is reflected by reflector B6 and then vertically incident on reflector A5, and then is reflected by reflector A5 and then is output horizontally.

[0019] Preferably, the vertical distance between the centers of the reflector A5 and the reflector B6 is adjustable.

[0020] The working principle of the utility model is as follows: two reflectors, namely, reflector A5 and reflector B6, are used to replace one reflector, and the optical path is vertically raised and lowered, so that the output pulse spot morphology is completely the same as the input pulse spot morphology, and the polarization state is also completely the same.

[0021] After the above-mentioned diffraction grating A1 is diffracted, it is diffracted to the diffraction grating B2, the optical path vertical lifter 4, the reflector A5, and the reflector B6, which can adopt applicable components and devices in the prior art, or adopt applicable components and devices in the prior art and adopt conventional technical means to construct.

[0022] The embodiments described above are only used to illustrate the technical ideas and features of the utility model, and their purpose is to enable technicians in the field to understand the content of the utility model and implement it accordingly. The patent scope of the utility model cannot be limited only by this embodiment, that is, any equivalent changes or modifications made to the spirit disclosed by the utility model still fall within the patent scope of the utility model.

Claims

1. A chirped pulse compressor that does not change the input light spot shape, characterized in that: It includes two mutually parallel diffraction gratings and a light path vertical riser; the two diffraction gratings are: diffraction grating A and diffraction grating B; after the incident light is incident on diffraction grating A, it is diffracted to diffraction grating B; the diffracted light beam is diffracted by diffraction grating B and then incident on the light path vertical riser, and the light path vertical riser changes the height of the outgoing light of diffraction grating B and returns at different heights parallel to the original light path.

2. The chirped pulse compressor without changing the input light spot shape according to claim 1, characterized in that: The optical path vertical lifter includes two mutually perpendicular mirrors, which are respectively reflector A and reflector B; reflector B is located below reflector A; a light beam from diffraction grating B is incident on reflector A or reflector B, and when the light beam is horizontally incident on reflector A, the light beam is reflected by reflector A and then vertically incident on reflector B downward, and is output horizontally after being reflected by reflector B; when the light beam is horizontally incident on reflector B, the light beam is reflected by reflector B and then vertically incident on reflector A upward, and is output horizontally after being reflected by reflector A.

3. The chirped pulse compressor without changing the input light spot shape according to claim 1, characterized in that: The vertical distance between the centers of reflector A and reflector B is adjustable.

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