Universal high-power attosecond optical field synthesis instrument and synthesis method

Abstract

The invention relates to a universal high-power attosecond optical field synthesis instrument and a synthesis method, and solves the technical problems that in the prior art, chirp reflectors are large in occupied space, small in number and difficult to adjust, synthesis of attosecond pulses cannot be achieved under the condition that dispersion differences of different wavebands of a wide spectrum are large, and the thermal stability is poor or the operation difficulty is large. The instrument comprises an optical field synthesis base and a heat dissipation device, an incident light filter and a beam splitter or a reflector are sequentially arranged on the light field synthesis base along a light path of incident light, the incident light is divided into three beams of reflected light, the three beams of reflected light are combined into emergent light by the beam splitter or the reflector after passing through the three channels respectively, and an emergent light path is provided with an emergent light filter; the three channels comprise optical filters, thin fused quartz wedge pairs, multi-pass reflection structures and a plurality of reflectors which are arranged on corresponding optical paths, and parameters of each element are respectively matched with wave bands of the corresponding optical paths.

Description

Technical Field

[0001] The present invention relates to light field synthesis technology, and in particular to a universal high-power attosecond light field synthesis instrument and a synthesis method. Background Art

[0002] In the traditional field of femtosecond laser pulse shaping, by controlling the amplitude, phase and polarization in the frequency domain, femtosecond laser pulses of various shapes can be flexibly obtained in the time domain. This technology provides an experimental technical means for studying the nonlinear interaction between lasers and atoms and molecules, thereby promoting the development of related research. With the development of science and technology and the deepening of research, people's demand for attosecond pulses with shorter pulse width and higher power is growing.

[0003] As a cutting-edge research direction in the current field of ultrafast optics, attosecond light field synthesis technology mainly involves the precise generation and control of continuous wide-spectrum ultrashort laser pulses. Compared with femtosecond laser pulses, attosecond pulses have the characteristics of extremely short time scale, wide spectrum, high energy and ultra-precise time control ability. They play an irreplaceable role in studying attosecond electron dynamics, atomic and molecular structure changes and nonlinear optical processes, especially isolated visible light attosecond pulses.

[0004] Isolated visible attosecond pulses can be used to manipulate the initial stages of chemical reactions and to interact more effectively with biological molecules, which is of great significance in research fields such as physical chemistry, catalytic reactions, biomedicine, and photosynthesis. For the study of isolated visible attosecond pulses, a key technical challenge is to develop a light field synthesis instrument that can generate high-power, high-stability, and highly controllable attosecond pulses.

[0005] The existing scheme for generating visible light attosecond pulses (also known as attosecond light pulses) is as follows:

[0006] The literature (Synthesized Light Transients. A. Wirth et al. Science 334, 195-200 (2011). DOI: 10.1126 / science.1210268.) proposed a light field synthesizer that can synthesize sub-periodic light pulses spanning the infrared, visible to ultraviolet light bands. The spectral range of the input light is subdivided into three bands of almost equal width. The dispersive chirped reflectors CM-VIS / UV, CM-VIS and CM-NIR are used to compress the pulses in each channel to a duration close to its bandwidth limit, and the relative delay is accurately controlled by a nanometer-level precision translation stage. The beam spot size is controlled by an aperture to adjust the pulse energy of each channel. Finally, a light pulse close to its bandwidth limit is generated, achieving a single pulse energy of about 0.3 mJ (ChNIR ~ 250 mJ, ChVIS ~ 35 mJ, ChVIS-UV ~ 15 mJ).

[0007] Based on the attosecond light pulses generated by the light field synthesizer, a full attosecond spectroscopy measurement system of attosecond pumping and attosecond detection can be established. However, the device has no cooling system and has poor thermal stability. The chirped reflectors therein use a 45-degree incidence method, which occupies a large space, has a small number, and are difficult to adjust. It is impossible to achieve the synthesis of attosecond pulses when the dispersion differences in different bands of a wide spectrum are large.

[0008] The literature (Optical attosecond pulses and tracking the nonlinear response of bound electrons. Hassan, M., Luu, T., Moulet, A. et al. Nature 530, 66–70 (2016).) and the literature (Attosecond light field synthesis. Husain Alqattan, Dandan Hui, Vladimir Pervak, Mohammed Th. Hassan APL Photonics 1 April 2022; 7 (4): 041301.) demonstrate two similar four-channel high-power attosecond light field synthesizers that can synthesize attosecond light pulses (380-400 as) in the visible light and nearby spectral range to achieve sub-femtosecond control and measurement of bound electron dynamics. The device broadens the laser pulse spectrum through nonlinear effects, generating an ultra-wideband spectrum of more than two optical octaves, covering the frequency range from near-infrared to deep ultraviolet, and is capable of producing attosecond light pulses with high energy and high repetition rate; and using a high-precision translation stage and variable neutral density filters, it can accurately control the relative delay and intensity of the pulses in each channel, thereby achieving precise control of the synthetic waveform; the peak power of the synthesized pulse can reach several terawatts (TW), while providing unprecedented time resolution and high peak power for exploring the movement of electrons inside matter.

[0009] However, the four-channel solution used by the above two devices has more channels than the three-channel solution, and the time-space overlap in the adjustment is more difficult, that is, the operation is more difficult. In addition, the chirped reflectors also use a 45-degree incidence method, which also has the problems of occupying a large space, a small number, and difficulty in adjustment. The dispersion compensation amount for the near-infrared and ultraviolet bands is similar, and the synthesis of attosecond pulses cannot be achieved when the dispersion difference between different bands of the wide spectrum is large. Therefore, a visible light attosecond light field synthesizer with higher universality for multiple broadened spectra, stronger thermal stability and high output optical power is needed. Summary of the invention

[0010] The purpose of the present invention is to solve the technical problems in the prior art that chirped mirrors occupy a large space, are few in number, are difficult to adjust, cannot synthesize attosecond pulses when the dispersion difference between different bands in a wide spectrum is large, and have poor thermal stability or are difficult to operate, and to provide a universal high-power attosecond light field synthesis instrument and synthesis method.

[0011] The idea of ​​the present invention is to design a small-angle, adjustable multi-pass reflection structure, and adjust the number of reflectors according to the different incident light dispersions while ensuring the consistency of the optical path of the three channels. While achieving dispersion compensation, the number of reflectors is minimized to reduce transmission losses.

[0012] In order to achieve the above objectives and realize the above concepts, the technical solutions provided by the present invention are as follows:

[0013] A general-purpose high-power attosecond light field synthesis instrument, used to synthesize CEP stable incident light, its special features are:

[0014] It includes a light field synthesis base and a heat dissipation device arranged in the light field synthesis base;

[0015] An incident filter, a first incident beam splitter, a second incident beam splitter and a third incident reflector are sequentially arranged on the light field synthesis base along the optical path of the incident light;

[0016] The first incident beam splitter splits the incident light into a first reflected light and a first transmitted light, the second incident beam splitter splits the first transmitted light into a second reflected light and a second transmitted light, and the third incident reflector reflects the second transmitted light into a third reflected light; wherein the first reflected light is in the ultraviolet light band; the second reflected light is in the visible light band; and the third reflected light is in the visible light to near infrared light band;

[0017] After the first reflected light, the second reflected light and the third reflected light pass through the first channel, the second channel and the third channel respectively, they are combined into outgoing light by the first outgoing beam splitter, the second outgoing beam splitter and the third outgoing reflector; an outgoing filter is arranged on the light field synthesis base along the outgoing light path;

[0018] The first channel, the second channel and the third channel all include filters, thin fused silica wedge pairs, multi-pass reflection structures and a plurality of reflectors arranged on corresponding optical paths, and the parameters are respectively adapted to the wavelength bands of the corresponding optical paths; the reflectors are used to change the direction of the optical paths and make the optical paths of the first channel, the second channel and the third channel the same;

[0019] The multi-pass reflection structure includes two parallel and oppositely arranged chirped reflector groups. The corresponding light beam is incident on one of the chirped reflector groups at 2 to 10 degrees through the reflector of the corresponding channel, and is emitted from the other chirped reflector group after at least two reflections, which is used for dispersion compensation and pulse width compression of the corresponding optical path.

[0020] The filters of the first channel, the second channel and the third channel as well as the incident filter and the exit filter are all used to limit the beam energy of the corresponding optical path and control the on-off of the optical path; the thin fused silica wedge pair is used for reverse compensation of dispersion of the corresponding optical path.

[0021] Further, among the first channel, the second channel and the third channel, at least two channels further include a linear translation stage;

[0022] The linear translation stage comprises a translation base and a plurality of reflectors arranged on the translation base and arranged parallel or vertically to each other, and is used to change the length of the corresponding optical path so that the optical paths of the first channel, the second channel and the third channel are the same.

[0023] Furthermore, the first channel, the second channel and the third channel all include a linear displacement stage; the linear displacement stage has two reflective mirrors, and the movement accuracy of the displacement base is less than 2 nm;

[0024] In the first channel, the second channel and the third channel, the filter, the thin fused quartz wedge pair, the multi-pass reflection structure and the linear translation stage are arranged in sequence along the corresponding optical paths.

[0025] Furthermore, the optical path direction of the incident light is recorded as the positive direction of the Y axis, and the direction perpendicular to the Y axis through the incident point to the right is the positive direction of the X axis; based on the top view angle of the light field synthesis base, the zero point of the XY coordinate system is located at the middle position of one side of the light field synthesis base;

[0026] The first incident beam splitter, the second exit beam splitter and the third incident reflector are arranged parallel to the angular bisectors of the second quadrant and the fourth quadrant; the first exit beam splitter, the second incident beam splitter and the third exit reflector are arranged parallel to the angular bisectors of the first quadrant and the third quadrant;

[0027] The first channel includes a first filter, a first thin fused silica wedge pair, a first reflection group A, a first multi-pass reflection structure, a first reflection group B and a first linear translation stage which are sequentially arranged along the optical path of the first reflected light;

[0028] The first reflection group A reflects the first reflected light from the negative direction of the X-axis to the positive direction of the X-axis, and is incident on the first multi-pass reflection structure at 2 to 10 degrees; the first reflection group B reflects the first reflected light emitted from the first multi-pass reflection structure at the same angle from the positive direction of the X-axis to the negative direction of the X-axis, and is incident on the reflection mirror on the first linear translation stage, and the first linear translation stage can move along the X-axis direction; the first linear translation stage reflects the first reflected light from the negative direction of the X-axis to the positive direction of the X-axis through the reflection mirror thereon, and is incident on the first exit beam splitter;

[0029] The second channel includes a second filter, a second thin fused silica wedge pair, a second reflection group A, a second multi-pass reflection structure, a second reflection group B and a second linear translation stage which are sequentially arranged along the optical path of the second reflected light;

[0030] The second reflection group A reflects the second reflected light from the positive direction of the X-axis to the negative direction of the X-axis, and is incident on the second multi-pass reflection structure at 2 to 10 degrees; the second reflection group B reflects the second reflected light emitted from the second multi-pass reflection structure at the same angle from the negative direction of the X-axis to the positive direction of the X-axis, and is incident on the reflection mirror on the second linear displacement stage, and the second linear displacement stage can move along the X-axis direction; the second linear displacement stage reflects the second reflected light from the positive direction of the X-axis to the negative direction of the X-axis through the reflection mirror thereon, and is incident on the second exit beam splitter;

[0031] The third channel includes a third filter, a third thin fused silica wedge pair, a third reflection group A, a third multi-pass reflection structure, a third reflection group B and a third linear translation stage which are sequentially arranged along the optical path of the third reflected light;

[0032] The third reflection group A reflects the third reflected light from the negative direction of the X-axis to the positive direction of the X-axis, and is incident on the third multi-pass reflection structure at 2 to 10°; the third reflection group B reflects the third reflected light emitted by the third multi-pass reflection structure at the same angle from the positive direction of the X-axis to the negative direction of the X-axis, and is incident on the reflector on the third linear displacement stage, and the third linear displacement stage can move along the X-axis direction; the third linear displacement stage reflects the third reflected light from the negative direction of the X-axis to the positive direction of the X-axis through the reflector thereon, and is incident on the third exit reflector.

[0033] Further, the first incident beam splitter, the second incident beam splitter, the third incident reflector, the first exit beam splitter, the second exit beam splitter and the third exit reflector are all arranged along the Y axis;

[0034] The first reflection group A includes a first reflection mirror I and a first reflection mirror II arranged perpendicularly thereto, wherein the first reflection mirror I is arranged along the angle bisector of the second quadrant and the fourth quadrant;

[0035] The first reflection group B includes a first reflector III and a first reflector IV arranged perpendicularly thereto, wherein the first reflector III is arranged along the bisector of the first quadrant and the third quadrant;

[0036] The second reflection group A includes a second reflector I and a second reflector II arranged perpendicularly thereto, wherein the second reflector I is arranged along the angle bisector of the first quadrant and the third quadrant;

[0037] The second reflection group B includes a second reflector III and a second reflector IV arranged perpendicularly thereto, and the second reflector III is arranged along the angle bisector of the second quadrant and the fourth quadrant;

[0038] The third reflector group A comprises a third reflector I and a third reflector II arranged perpendicularly thereto, wherein the third reflector I is arranged along the angle bisector of the second quadrant and the fourth quadrant;

[0039] The third reflector group B includes a third reflector III and a third reflector IV arranged perpendicularly thereto, and the third reflector III is arranged along an angle bisector of the first quadrant and the third quadrant.

[0040] Further, the chirped reflector group in the multi-pass reflective structure includes at least two chirped reflectors arranged side by side, and the chirped reflectors are threadedly mounted on the light field synthesis base;

[0041] The reflectors of the first channel, the second channel and the third channel are threadedly mounted on the light field synthesis base;

[0042] On the light field synthesis base, a row of threaded mounting holes parallel to the chirped reflector group are provided near each multi-pass reflector structure, for correspondingly reinstalling the reflectors of the first channel, the second channel and the third channel when adjusting and removing the chirped reflectors;

[0043] Alternatively, the chirped reflector group in the multi-pass reflective structure is a strip-shaped chirped reflector.

[0044] Furthermore, the chirped reflector group includes five chirped reflectors arranged side by side, and the interval between two adjacent chirped reflectors is 5 mm; the reflectors of the first channel, the second channel and the third channel make the corresponding light beams incident on the corresponding chirped reflector group at 5°.

[0045] Further, the reflector is a chirped reflector or a high-reflection plane mirror;

[0046] The incident filter, the exit filter, the first filter, the second filter and the third filter are all variable neutral density filters;

[0047] The light field synthesis base is made of aluminum;

[0048] The heat dissipation device comprises a water-cooling heat dissipation pipe embedded in the light field synthesis base, and a water-cooling device connected to the water-cooling heat dissipation pipe; the water-cooling heat dissipation pipe is formed by splicing at least three U-shaped pipes connected end to end.

[0049] The present invention also provides a universal high-power attosecond light field synthesis method, which is special in that it includes the following steps:

[0050] S0, making any one of the above-mentioned general-purpose high-power attosecond light field synthesis instruments, aligning a laser generating incident light with an incident filter;

[0051] S1, turn on the incident filter and the output filter; start the laser to generate incident light and lock the synchronization between the channels of the incident light;

[0052] S2, adjusting the positions and angles of the reflectors of the first channel, the second channel, and the third channel so that the optical paths and output light spot positions of the first channel, the second channel, and the third channel are the same;

[0053] S3, determining the structure of the chirped reflector group in the multi-pass reflective structure;

[0054] If the chirped reflector group is a plurality of chirped reflectors arranged side by side, then according to the requirements of the incident light, the number of chirped reflectors in the multi-pass reflective structure is adjusted accordingly, and the relative number of chirped reflectors and high-reflection plane mirrors in the reflectors is adjusted to increase or decrease the dispersion compensation amount, and then step S4 is executed;

[0055] If the chirped reflector group is a bar-shaped chirped reflector, directly execute step S4;

[0056] S4, splitting the incident light into a first reflected light, a second reflected light and a third reflected light through a first incident beam splitter, a second incident beam splitter and a third incident reflecting mirror;

[0057] S5, respectively performing dispersion reverse compensation on the first reflected light, the second reflected light and the third reflected light through a pair of thin fused silica wedges, and performing dispersion compensation and compressing the pulse width through a multi-pass reflection structure;

[0058] S6, combining the first reflected light, the second reflected light and the third reflected light into an output light through a first output beam splitter, a second output beam splitter and a third output reflecting mirror to obtain an attosecond light pulse.

[0059] The beneficial effects of the present invention compared with the prior art are as follows:

[0060] 1. The present invention provides a universal high-power attosecond light field synthesis instrument, which designs a small-angle, adjustable multi-pass reflection structure with a compact and flexible structure. While ensuring that the optical path of the three channels is consistent, the dispersion compensation amount can be changed by adjusting the number of chirped reflectors according to the dispersion of different incident light. While achieving dispersion compensation, the number of chirped reflectors can be minimized to reduce transmission loss, maximize transmission efficiency, expand the adjustable range of dispersion, improve the universality of attosecond light field synthesizers for a variety of broadened spectra, solve the problem of large dispersion differences in different bands of a wide spectrum, and improve the output light power and stability, thereby making the light field synthesis instrument more applicable.

[0061] 2. The present invention provides a universal high-power attosecond light field synthesis instrument, in which the chirped reflectors in the multi-pass reflection structure are detachable, and a row of threaded holes is additionally provided on the periphery of the multi-pass reflection structure of each channel, so that the number of chirped reflectors can be flexibly adjusted according to the input light requirements, and the reflectors of the channel can be re-installed in the reserved threaded mounting holes to change the position of the components to complete the adjustment, and the adjustment method is simple and the operation difficulty is low.

[0062] 3. The present invention provides a universal high-power attosecond light field synthesis instrument, in which the multi-pass reflection structure adopts a small-angle solution, that is, dispersion compensation and pulse width compression are achieved through multiple 5° reflections, which improves space utilization and ensures the compactness of the structure.

[0063] 4. The present invention provides a universal high-power attosecond light field synthesis instrument, in which water-cooled heat pipes are evenly embedded in the base of the light field synthesizer, and a water cooling device is used for heat dissipation, thereby ensuring that the multi-pass reflection structure has good heat dissipation conditions, improving the stability of the equipment, and increasing the receivable light pulse power, thereby increasing the output light power, and realizing higher power and higher stability attosecond photosynthesis.

[0064] 5. The present invention provides a universal high-power attosecond light field synthesis method, which adopts a three-channel light field synthesis scheme with low adjustment difficulty. By disassembling the chirped reflector and other reflectors in the multi-pass reflection structure, the dispersion compensation amount can be flexibly adjusted to maximize the transmission efficiency and expand the adjustable range of dispersion. The problem that the dispersion difference between different bands in a wide spectrum is large and the synthesis of attosecond pulses cannot be achieved, such as the output light of a multi-stage OPA system, is solved, thereby realizing dispersion-controllable high-power visible light attosecond light field synthesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a structural schematic diagram of an embodiment of a universal high-power attosecond light field synthesis instrument of the present invention (from a top view);

[0066] Figure 2 is a schematic structural diagram of a multi-pass reflection structure in an embodiment of the present invention;

[0067] Figure 3 Schematic diagram of the structure of the heat dissipation device in the embodiment of the present invention (water cooling device is omitted);

[0068] Figure 4 is a diagram showing the simulation results of light field synthesis simulation performed on an embodiment of the present invention;

[0069] Figure 5 It is a simulation result diagram of the light field synthesis simulation after changing the channel parameters of the embodiment of the present invention, wherein A is a light field waveform diagram of changing the pulse width of the third channel, B is a light field waveform diagram of changing the relative intensity of the third channel, C is a light field waveform diagram of changing the third channel pulse CEP, and D is a light field waveform diagram of changing the third channel pulse delay.

[0070] Figure Number:

[0071] 01-Light field synthesis base; 02-Heat dissipation device;

[0072] 1- incident filter; 2- exit filter;

[0073] 3-first incident beam splitter; 4-first filter; 5-first thin fused silica wedge pair; 6-first reflector I; 7-first reflector II; 8-first multi-pass reflection structure; 9-first reflector III; 10-first reflector IV; 11-first linear translation stage; 12-first exit beam splitter;

[0074] 13-second incident beam splitter; 14-second filter; 15-second thin fused silica wedge pair; 16-second reflector I; 17-second reflector II; 18-second multi-pass reflection structure; 19-second reflector III; 20-second reflector IV; 21-second linear translation stage; 22-second exit beam splitter;

[0075] 23-third incident reflector; 24-third filter; 25-third thin fused silica wedge pair; 26-third reflector I; 27-third reflector II; 28-third multi-pass reflective structure; 29-third reflector III; 30-third reflector IV; 31-third linear translation stage; 32-third exit reflector. DETAILED DESCRIPTION

[0076] The specific technical solutions in the embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0077] Figure 1 A universal high-power attosecond light field synthesis instrument provided in an embodiment of the present invention is used to synthesize CEP-stabilized incident light, including a light field synthesis base 01 and a heat dissipation device 02 arranged in the light field synthesis base 01.

[0078] An incident filter 1, a first incident beam splitter 3, a second incident beam splitter 13 and a third incident reflector 23 are sequentially arranged on the light field synthesis base 01 along the optical path of the incident light; the first incident beam splitter 3 splits the incident light into a first reflected light and a first transmitted light, the second incident beam splitter 13 splits the first transmitted light into a second reflected light and a second transmitted light, and the third incident reflector 23 reflects the second transmitted light into a third reflected light; wherein the first reflected light is in the ultraviolet light band (CM-UV); the second reflected light is in the visible light band (CM-VIS); and the third reflected light is in the visible light to near infrared light band (CM-VIS / NIR).

[0079] After the first reflected light, the second reflected light and the third reflected light pass through the first channel, the second channel and the third channel respectively, they are combined into output light by the first output beam splitter 12, the second output beam splitter 22 and the third output reflector 32; an output filter 2 is arranged on the light field synthesis base 01 along the output light path.

[0080] The first channel, the second channel and the third channel all include filters, thin fused quartz wedge pairs, multi-pass reflection structures, linear translation stages, and multiple reflectors, which are sequentially arranged on the corresponding optical paths, and the parameters of each component are adapted to the wavelength band of the corresponding optical path; the reflectors are used to change the direction of the optical path and make the optical paths of the first channel, the second channel and the third channel the same.

[0081] The filters of the first channel, the second channel and the third channel, as well as the incident filter 1 and the exit filter 2 are all used to limit the beam energy of the corresponding optical path and control the on-off of the optical path; the thin fused silica wedge pair is used for reverse compensation of dispersion of the corresponding optical path.

[0082] The linear displacement stage includes a displacement base and two mutually perpendicular reflectors arranged on the displacement base, which are used to change the length of the corresponding optical path so that the optical paths of the first channel, the second channel and the third channel are the same, and the relative delay time between the channels is controlled at the same time. The movement accuracy of the displacement base is 1nm (corresponding to a time accuracy of 6.7 attoseconds). In other embodiments of the present invention, only two of the three channels need to be equipped with linear displacement stages to adjust the optical path, that is, the unmounted channels are regarded as reference objects, which can reduce costs.

[0083] Specifically:

[0084] The optical path direction of the incident light is recorded as the positive direction of the Y axis, and the direction perpendicular to the Y axis through the incident point to the right is the positive direction of the X axis; based on the top view angle of the light field synthesis base 01, the zero point of the XY coordinate system is located in the middle position of one side of the light field synthesis base 01.

[0085] The first incident beam splitter 3, the second exit beam splitter 22 and the third incident reflector 23 are arranged parallel to the angular bisectors of the second and fourth quadrants; the first exit beam splitter 12, the second incident beam splitter 13 and the third exit reflector 32 are arranged parallel to the angular bisectors of the first and third quadrants. The first incident beam splitter 3, the second incident beam splitter 13, the third incident reflector 23, the first exit beam splitter 12, the second exit beam splitter 22 and the third exit reflector 32 are all arranged along the Y axis.

[0086] refer to Figure 2The chirped reflector group in the multi-pass reflection structure includes five chirped reflectors arranged side by side, and the chirped reflectors are threadedly mounted on the light field synthesis base 01; the reflectors of the first channel, the second channel and the third channel are threadedly mounted on the light field synthesis base 01; on the light field synthesis base 01, a row of threaded mounting holes parallel to the chirped reflector group are provided near each multi-pass reflection structure, which are used to reinstall the reflectors of the first channel, the second channel and the third channel when adjusting and disassembling the chirped reflectors, and adjust their positions to expand the adjustable range of dispersion. In other embodiments of the present invention, the reflectors can also be fixed by means such as slide rails, so that their installation positions are flexible and adjustable. The spacing between two adjacent chirped reflectors is 5 mm; the reflectors of the first channel, the second channel and the third channel make the corresponding light beams incident on the corresponding chirped reflector group at 5°.

[0087] The first channel includes a first filter 4, a first thin fused quartz wedge pair 5, a first reflection group A, a first multi-pass reflection structure 8, a first reflection group B and a first linear translation stage 11, which are arranged in sequence along the optical path of the first reflected light; the first reflection group A includes a first reflector I6 and a first reflector II7 arranged perpendicularly thereto, and the first reflector I6 is arranged along the angular bisector of the second quadrant and the fourth quadrant; the first reflection group B includes a first reflector III9 and a first reflector IV10 arranged perpendicularly thereto, and the first reflector III9 is ​​arranged along the angular bisector of the first quadrant and the third quadrant.

[0088] The first reflection group A reflects the first reflected light from the negative direction of the X-axis to the positive direction of the X-axis, and is incident on the first multi-pass reflection structure 8 at 5°; the first reflection group B reflects the first reflected light emitted by the first multi-pass reflection structure 8 at the same angle from the positive direction of the X-axis to the negative direction of the X-axis, and is incident on the reflection mirror on the first linear translation stage 11, and the first linear translation stage 11 can move along the X-axis direction; the first linear translation stage 11 reflects the first reflected light from the negative direction of the X-axis to the positive direction of the X-axis through the reflection mirror thereon, and is incident on the first exit beam splitter 12.

[0089] The first reflected light is in the ultraviolet band. After passing through the first filter 4, it passes through the first thin molten silicon wedge pair 5 for dispersion reverse compensation, and then passes through the first reflection group A, the first multi-pass reflection structure 8, and the first reflection group B for 14 reflections (the maximum number of reflections in this embodiment is designed after comprehensively considering the energy loss caused by the reflection and the band dispersion compensation amount) to perform dispersion compensation and compress the pulse width, and then enters the first linear displacement stage 11. By adjusting the relative position of the displacement base of the first linear displacement stage 11, the optical path of the first channel and the other channels are controlled to be the same and the phase is consistent, thereby ensuring the quality of the synthetic beam.

[0090] The second channel includes a second filter 14, a second thin fused silica wedge pair 15, a second reflection group A, a second multi-pass reflection structure 18, a second reflection group B and a second linear translation stage 21, which are arranged in sequence along the optical path of the second reflected light; the second reflection group A includes a second reflector I16 and a second reflector II17 arranged perpendicularly thereto, and the second reflector I16 is arranged along the angular bisector of the first quadrant and the third quadrant; the second reflection group B includes a second reflector III19 and a second reflector IV20 arranged perpendicularly thereto, and the second reflector III19 is arranged along the angular bisector of the second quadrant and the fourth quadrant.

[0091] The second reflection group A reflects the second reflected light from the positive direction of the X-axis to the negative direction of the X-axis, and is incident on the second multi-pass reflection structure 18 at 5°; the second reflection group B reflects the second reflected light emitted from the second multi-pass reflection structure 18 at the same angle from the negative direction of the X-axis to the positive direction of the X-axis, and is incident on the reflection mirror on the second linear translation stage 21, and the second linear translation stage 21 can move along the X-axis direction; the second linear translation stage 21 reflects the second reflected light from the positive direction of the X-axis to the negative direction of the X-axis through the reflection mirror thereon, and is incident on the second exit beam splitter 22;

[0092] The second reflected light is in the visible light band. After being cut by the second filter 14 to have the same energy as the first channel light, its processing method is similar to that of the first reflected light.

[0093] The third channel includes a third filter 24, a third thin fused silica wedge pair 25, a third reflection group A, a third multi-pass reflection structure 28, a third reflection group B and a third linear translation stage 31, which are arranged in sequence along the optical path of the third reflected light; the third reflection group A includes a third reflector I26 and a third reflector II27 arranged perpendicularly thereto, and the third reflector I26 is arranged along the angular bisector of the second quadrant and the fourth quadrant; the third reflection group B includes a third reflector III29 and a third reflector IV30 arranged perpendicularly thereto, and the third reflector III29 is arranged along the angular bisector of the first quadrant and the third quadrant.

[0094] The third reflection group A reflects the third reflected light from the negative direction of the X-axis to the positive direction of the X-axis, and is incident on the third multi-pass reflection structure 28 at 5°; the third reflection group B reflects the third reflected light emitted from the third multi-pass reflection structure 28 at the same angle from the positive direction of the X-axis to the negative direction of the X-axis, and is incident on the reflector on the third linear displacement stage 31, and the third linear displacement stage 31 can move along the X-axis direction; the third linear displacement stage 31 reflects the third reflected light from the negative direction of the X-axis to the positive direction of the X-axis through the reflector thereon, and is incident on the third output reflector 32.

[0095] The third reflected light is in the visible to infrared light band. After being cut by the third filter 24 to have the same energy as the first channel light, the processing method thereof is similar to that of the first reflected light.

[0096] By fixing the optical path length of one channel as a reference and adjusting the linear translation stages of the other two channels, the optical path lengths of the three channels can be controlled to be the same.

[0097] In the embodiment of the present invention, the reflector is a chirped reflector or a high-reflection plane mirror (depending on the actual dispersion compensation amount required), and the high-reflection plane mirror is selected from a silver reflector or an aluminum reflector as required; the high-reflection plane mirror replaces the chirped reflector when no more dispersion compensation is required. The incident filter 1, the output filter 2, the first filter 4, the second filter 14 and the third filter 24 are all variable neutral density filters. The chirped reflector is used to compensate for the dispersion of the input light pulse and the dispersion introduced by other transmission elements (thin fused silica wedge pairs, variable neutral density filters and beam splitters) in each channel. Its parameters are selected according to the corresponding channels to match the control bands of the three channels respectively.

[0098] refer to Figure 3 , the light field synthesis base 01 is an aluminum part. The heat dissipation device 02 includes a water-cooled heat dissipation pipe embedded in the light field synthesis base 01, and a water-cooled device connected to the water-cooled heat dissipation pipe; the water-cooled heat dissipation pipe is composed of at least three U-shaped pipes connected end to end. For relatively high-power lasers, the instrument will generate high heat when working, which will affect the working state of each optical component. The introduction of water cooling can timely remove the heat conducted during the operation of the instrument, improve the stability of the equipment and the receivable light pulse power, and greatly reduce the heat dissipation pressure.

[0099] In other embodiments of the present invention, the chirped reflector group in the multi-pass reflection structure may also be an integrated strip-shaped chirped reflector, which loses the advantage of flexible and adjustable number of chirped reflectors (adjustable dispersion compensation amount), but correspondingly simplifies the installation process and makes adjustment more convenient.

[0100] The steps of the synthesis method of the embodiment of the present invention are as follows:

[0101] S0, making a universal high-power attosecond light field synthesis instrument, aligning the laser generating the incident light with the incident filter 1;

[0102] S1, turn on incident filter 1 and exit filter 2; start the laser to generate incident light and lock the synchronization between the channels of the incident light, that is, the time interference of the cross-band parts of different channels;

[0103] S2, adjusting the positions and angles of the reflectors of the first channel, the second channel and the third channel so that the optical paths and output light spot positions of the first channel, the second channel and the third channel are the same, that is, the time and space of the output lights of the three channels overlap;

[0104] S3, according to the requirements of the incident light, correspondingly adjusting the number of chirped reflectors in the multi-pass reflective structure, and adjusting the relative number of chirped reflectors and high-reflective plane mirrors in the reflectors to increase or decrease the dispersion compensation amount;

[0105] Generally speaking, the chirped reflectors in the multi-pass reflection structure are removed in pairs, so that the corresponding outgoing light paths are parallel to the original outgoing light paths, so only the corresponding reflectors need to be reinstalled;

[0106] S4, splitting the incident light into a first reflected light, a second reflected light and a third reflected light through the first incident beam splitter 3, the second incident beam splitter 13 and the third incident reflecting mirror 23;

[0107] S5, respectively performing dispersion reverse compensation on the first reflected light, the second reflected light and the third reflected light through a pair of thin fused silica wedges, and performing dispersion compensation and compressing the pulse width through a multi-pass reflection structure;

[0108] S6, combining the first reflected light, the second reflected light and the third reflected light into an output light through the first output beam splitter 12, the second output beam splitter 22 and the third output reflecting mirror 32 to obtain an attosecond light pulse.

[0109] Figure 4 This is a simulation result diagram of the present invention, wherein the first three rows are light field simulation results of three-channel pulses, and the last row is a light field simulation result after synthesis, with a pulse width of approximately 360as.

[0110] Figure 5 The simulation results after changing the channel parameters of the embodiment of the present invention are shown in Figure 1, where A is the light field waveform after changing the pulse width of the third channel (7fs, 7fs, 7fs to 7fs, 7fs, 9fs), B is the light field waveform after changing the relative intensity of the third channel (1:1:1 to 1:1:3), C is the light field waveform after changing the CEP of the third channel pulse (0 to pi / 4), and D is the light field waveform after changing the pulse delay of the third channel (0 to 2.2fs). CEP is the pulse carrier envelope phase.

[0111] For A, changing the channel pulse width means changing the dispersion compensation amount of different channels; for B, the relative intensity of each channel can be adjusted according to the variable neutral density filter, and the light intensity of different channels can be measured with a power meter to match the ratio of light intensity in the simulation; for C, this embodiment requires that the CEP of each channel is stabilized at zero in order to synthesize isolated attosecond light pulses; for D, the pulse delay can be made zero by adjusting the optical path of each channel to be the same. If the optical path of the three channels is different, different pulse delays will be generated.

[0112] The above content is only an embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A general-purpose high-power attosecond light field synthesis instrument for synthesizing CEP-stabilized incident light, characterized in that: It comprises a light field synthesis base (01) and a heat dissipation device (02) arranged in the light field synthesis base (01); An incident filter (1), a first incident beam splitter (3), a second incident beam splitter (13) and a third incident reflector (23) are sequentially arranged on the light field synthesis base (01) along the optical path of the incident light; The first incident beam splitter (3) splits the incident light into a first reflected light and a first transmitted light, the second incident beam splitter (13) splits the first transmitted light into a second reflected light and a second transmitted light, and the third incident reflector (23) reflects the second transmitted light into a third reflected light; wherein the first reflected light is in the ultraviolet light band; the second reflected light is in the visible light band; and the third reflected light is in the visible light to near infrared light band; After the first reflected light, the second reflected light and the third reflected light pass through the first channel, the second channel and the third channel respectively, they are combined into outgoing light by the first outgoing beam splitter (12), the second outgoing beam splitter (22) and the third outgoing reflector (32); an outgoing filter (2) is arranged on the light field synthesis base (01) along the outgoing light optical path; The first channel, the second channel and the third channel all include filters, thin fused silica wedge pairs, multi-pass reflection structures and a plurality of reflectors arranged on corresponding optical paths, and the parameters are respectively adapted to the wavelength bands of the corresponding optical paths; the reflectors are used to change the direction of the optical path and make the optical paths of the first channel, the second channel and the third channel the same; The multi-pass reflection structure includes two parallel and oppositely arranged chirped reflector groups, and the corresponding light beam is incident on one of the chirped reflector groups at 2 to 10 degrees through the reflector of the corresponding channel, and is emitted from the other chirped reflector group after at least two reflections, so as to compensate for the dispersion of the corresponding optical path and compress the pulse width; The optical filters of the first channel, the second channel and the third channel, as well as the incident optical filter (1) and the output optical filter (2) are all used to limit the energy of the light beam of the corresponding optical path and control the on-off of the optical path; the thin fused silica wedge pair is used for reverse compensation of dispersion of the corresponding optical path.

2. A general-purpose high-power attosecond light field synthesis instrument according to claim 1, characterized in that: At least two of the first channel, the second channel and the third channel further include a linear translation stage; The linear translation stage includes a translation base and a plurality of reflectors arranged parallel or perpendicular to each other on the translation base, which are used to change the length of the corresponding optical path so that the optical paths of the first channel, the second channel and the third channel are the same.

3. A general-purpose high-power attosecond light field synthesis instrument according to claim 2, characterized in that: The first channel, the second channel and the third channel all include a linear displacement stage; the linear displacement stage has two reflectors, and the movement accuracy of the displacement base is less than 2nm; In the first channel, the second channel and the third channel, the filter, the thin fused silica wedge pair, the multi-pass reflection structure and the linear translation stage are sequentially arranged along the corresponding optical paths.

4. A general-purpose high-power attosecond light field synthesis instrument according to claim 3, characterized in that: The optical path direction of the incident light is recorded as the positive direction of the Y axis, and the direction perpendicular to the Y axis through the incident point to the right is recorded as the positive direction of the X axis; based on the top view angle of the light field synthesis base (01), the zero point of the XY coordinate system is located at the middle position of one side of the light field synthesis base (01); The first incident beam splitter (3), the second exit beam splitter (22) and the third incident reflector (23) are arranged in parallel with the angular bisectors of the second quadrant and the fourth quadrant; the first exit beam splitter (12), the second incident beam splitter (13) and the third exit reflector (32) are arranged in parallel with the angular bisectors of the first quadrant and the third quadrant; The first channel comprises a first filter (4), a first thin fused silica wedge pair (5), a first reflection group A, a first multi-pass reflection structure (8), a first reflection group B and a first linear translation stage (11) which are sequentially arranged along the optical path of the first reflected light; The first reflection group A reflects the first reflected light from the negative direction of the X-axis to the positive direction of the X-axis, and the reflected light is incident on the first multi-pass reflection structure (8) at 2 to 10 degrees; the first reflection group B reflects the first reflected light emitted from the first multi-pass reflection structure (8) at the same angle from the positive direction of the X-axis to the negative direction of the X-axis, and the reflected light is incident on the reflection mirror on the first linear displacement stage (11), and the first linear displacement stage (11) can move along the X-axis direction; the first linear displacement stage (11) reflects the first reflected light from the negative direction of the X-axis to the positive direction of the X-axis through the reflection mirror thereon, and the reflected light is incident on the first exit beam splitter (12); The second channel comprises a second filter (14), a second thin fused silica wedge pair (15), a second reflection group A, a second multi-pass reflection structure (18), a second reflection group B and a second linear translation stage (21) which are sequentially arranged along the optical path of the second reflected light; The second reflection group A reflects the second reflected light from the positive direction of the X-axis to the negative direction of the X-axis, and the reflected light is incident on the second multi-pass reflection structure (18) at an angle of 2 to 10 degrees; the second reflection group B reflects the second reflected light emitted from the second multi-pass reflection structure (18) at the same angle from the negative direction of the X-axis to the positive direction of the X-axis, and the reflected light is incident on the second linear displacement stage (21), and the second linear displacement stage (21) can move along the X-axis direction; the second linear displacement stage (21) reflects the second reflected light from the positive direction of the X-axis to the negative direction of the X-axis, and the reflected light is incident on the second exit beam splitter (22); The third channel comprises a third filter (24), a third thin fused silica wedge pair (25), a third reflection group A, a third multi-pass reflection structure (28), a third reflection group B and a third linear displacement stage (31) which are sequentially arranged along the optical path of the third reflected light; The third reflection group A reflects the third reflected light from the negative direction of the X-axis to the positive direction of the X-axis, and the reflected light is incident on the third multi-pass reflection structure (28) at an angle of 2 to 10 degrees; the third reflection group B reflects the third reflected light emitted from the third multi-pass reflection structure (28) at the same angle from the positive direction of the X-axis to the negative direction of the X-axis, and the reflected light is incident on the third linear displacement stage (31), and the third linear displacement stage (31) can move along the X-axis direction; the third linear displacement stage (31) reflects the third reflected light from the negative direction of the X-axis to the positive direction of the X-axis, and the reflected light is incident on the third output reflection mirror (32).

5. A general-purpose high-power attosecond light field synthesis instrument according to claim 4, characterized in that: The first incident beam splitter (3), the second incident beam splitter (13), the third incident reflector (23), the first exit beam splitter (12), the second exit beam splitter (22) and the third exit reflector (32) are all arranged along the Y axis; The first reflection group A comprises a first reflection mirror I (6) and a first reflection mirror II (7) arranged perpendicularly thereto, wherein the first reflection mirror I (6) is arranged along the bisector of the angles of the second quadrant and the fourth quadrant; The first reflection group B comprises a first reflection mirror III (9) and a first reflection mirror IV (10) arranged perpendicularly thereto, wherein the first reflection mirror III (9) is arranged along an angle bisector of the first quadrant and the third quadrant; The second reflective group A comprises a second reflector I (16) and a second reflector II (17) arranged perpendicularly thereto, wherein the second reflector I (16) is arranged along an angle bisector of the first quadrant and the third quadrant; The second reflection group B comprises a second reflection mirror III (19) and a second reflection mirror IV (20) arranged perpendicularly thereto, and the second reflection mirror III (19) is arranged along the angular bisector of the second quadrant and the fourth quadrant; The third reflector group A comprises a third reflector I (26) and a third reflector II (27) arranged perpendicularly thereto, wherein the third reflector I (26) is arranged along the angular bisector of the second quadrant and the fourth quadrant; The third reflector group B comprises a third reflector III (29) and a third reflector IV (30) arranged perpendicularly thereto. The third reflector III (29) is arranged along an angle bisector of the first quadrant and the third quadrant.

6. A general-purpose high-power attosecond light field synthesis instrument according to any one of claims 1 to 5, characterized in that: The chirped reflector group in the multi-pass reflective structure comprises at least two chirped reflectors arranged side by side, and the chirped reflectors are threadedly mounted on the light field synthesis base (01); The reflectors of the first channel, the second channel and the third channel are threadedly mounted on the light field synthesis base; The light field synthesis base (01) is provided with a row of threaded mounting holes parallel to the chirped reflector group at positions close to each multi-pass reflector structure, for correspondingly reinstalling the reflectors of the first channel, the second channel and the third channel when adjusting and removing the chirped reflectors; Alternatively, the chirped reflector group in the multi-pass reflective structure is a strip-shaped chirped reflector.

7. A general-purpose high-power attosecond light field synthesis instrument according to claim 6, characterized in that: The chirped reflector group includes five chirped reflectors arranged side by side, and the interval between two adjacent chirped reflectors is 5 mm; the reflectors of the first channel, the second channel and the third channel enable the corresponding light beams to be incident on the corresponding chirped reflector group at 5°.

8. A general-purpose high-power attosecond light field synthesis instrument according to claim 1, characterized in that: The reflector is a chirped reflector or a high-reflection plane mirror; The incident filter (1), the exit filter (2), the first filter (4), the second filter (14) and the third filter (24) are all variable neutral density filters; The light field synthesis base (01) is an aluminum part; The heat dissipation device (02) comprises a water-cooling heat dissipation pipe embedded in the light field synthesis base (01), and a water cooling device connected to the water-cooling heat dissipation pipe; the water-cooling heat dissipation pipe is formed by splicing at least three U-shaped pipes connected end to end.

9. A universal high-power attosecond light field synthesis method, characterized in that: The steps include: S0, manufacturing the universal high-power attosecond light field synthesis instrument as described in any one of claims 1 to 8, and aligning a laser generating incident light with the incident filter (1); S1, turn on the incident filter (1) and the exit filter (2); Start the laser to generate incident light and lock the synchronization between the channels of incident light; S2, adjusting the positions and angles of the reflectors of the first channel, the second channel and the third channel so that the optical paths and output light spot positions of the first channel, the second channel and the third channel are the same; S3, determining the structure of the chirped reflector group in the multi-pass reflective structure; If the chirped reflector group is a plurality of chirped reflectors arranged side by side, then according to the requirements of the incident light, the number of chirped reflectors in the multi-pass reflective structure is adjusted accordingly, and the relative number of chirped reflectors and high-reflection plane mirrors in the reflectors is adjusted to increase or decrease the dispersion compensation amount, and then step S4 is executed; If the chirped reflector group is a bar-shaped chirped reflector, directly execute step S4; S4, splitting the incident light into first reflected light, second reflected light and third reflected light by means of the first incident beam splitter (3), the second incident beam splitter (13) and the third incident reflecting mirror (23); S5, respectively performing dispersion reverse compensation on the first reflected light, the second reflected light and the third reflected light through the thin fused silica wedge pair, and performing dispersion compensation and compressing pulse width through the multi-pass reflection structure; S6, combining the first reflected light, the second reflected light and the third reflected light into an output light through the first output beam splitter (12), the second output beam splitter (22) and the third output reflecting mirror (32), to obtain an attosecond light pulse.

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