A general high-power attosecond light field synthesizer and a synthesis method thereof

Abstract

The present application relates to a kind of general high-power attosecond light field synthesizer and synthesis method, solve the technical problems that existing technology exists chirp mirror occupies larger space, quantity is less, difficult to adjust, for the case that the dispersion difference of different waveband of wide spectrum is larger, cannot realize the synthesis of attosecond pulse, and poor thermal stability or difficult operation.The instrument of the present application includes light field synthesis base and heat dissipation device;Light field synthesis base is sequentially provided with incident filter and beam splitter or mirror along the optical path of incident light, which is divided into three reflected lights, and is combined into emergent light by beam splitter or mirror after passing through three channels respectively, and the optical path of emergent light is provided with emergent filter;Three channels include filter, thin fused quartz wedge pair, multi-pass reflection structure and multiple mirrors arranged on corresponding optical path, and the parameters of each element are adapted to the waveband of corresponding optical path respectively.

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 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, a variety of femtosecond laser pulse shapes can be flexibly generated in the time domain. This technique provides an experimental means for studying the nonlinear interactions 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, there is a growing demand for attosecond pulses with shorter pulse widths and higher powers.

[0003] Attosecond light field synthesis, a cutting-edge research direction in ultrafast optics, primarily involves the precise generation and control of continuous, broad-spectrum, ultrashort laser pulses. Compared to femtosecond laser pulses, attosecond pulses possess extremely short timescales, broad spectrum, high energy, and ultra-precise temporal control. They are particularly valuable in studying attosecond electron dynamics, changes in atomic and molecular structure, and nonlinear optical processes, particularly isolated visible light attosecond pulses.

[0004] Isolated visible attosecond pulses can be used to manipulate the initial stages of chemical reactions and generate more efficient interactions with biomolecules, holding significant research significance in fields such as physical chemistry, catalysis, biomedicine, and photosynthesis. A key technical challenge in the study of isolated visible attosecond pulses is the development of light field synthesis instruments capable of generating high-power, high-stability, and highly controllable attosecond pulses.

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

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

[0007] Based on the attosecond light pulses generated by this light field synthesizer, a full attosecond spectroscopy measurement system with attosecond pumping and attosecond detection can be established. However, this device has no cooling system and has poor thermal stability. In addition, the chirped mirrors use a 45-degree incidence method, which takes up a large space, is few in number, and is difficult to adjust. It cannot achieve the synthesis of attosecond pulses when the dispersion differences between different bands in 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, which can synthesize attosecond light pulses (380-400as) 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 synthesized waveform; the peak power of the synthesized pulse can reach the terawatt (TW) level, while providing unprecedented time resolution and high peak power for exploring the motion of electrons inside matter.

[0009] However, the four-channel approach used in the two aforementioned devices has more channels than the three-channel approach, making spatiotemporal overlap more challenging to adjust, which in turn makes operation more difficult. Furthermore, the chirped mirrors also use a 45-degree incidence method, resulting in a large footprint, a small number of them, and difficulty adjusting them. The dispersion compensation for the near-infrared and ultraviolet bands is similar, making it impossible to synthesize attosecond pulses when dispersion varies significantly across a wide spectrum. Therefore, a visible light attosecond light field synthesizer with greater universality for multiple broadened spectra, enhanced thermal stability, and high output power is needed. Summary of the Invention

[0010] The purpose of the present invention is to solve the technical problems in the prior art, such as the large space occupied by chirped mirrors, the small number of chirped mirrors, the difficulty in adjusting them, the inability to synthesize attosecond pulses when the dispersion differences between different bands in a wide spectrum are large, and the poor thermal stability or the difficulty in operation. The present invention provides a universal high-power attosecond light field synthesis instrument and synthesis method.

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

[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-stabilized incident light. Its special features include:

[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 provided on the light field synthesis base along the outgoing light path;

[0018] The first channel, the second channel, and the third channel each include a filter, a pair of thin fused silica wedges, a multi-pass reflection structure, and a plurality of reflectors arranged on the corresponding optical path, and the parameters 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 path lengths 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 chirped reflector group at an angle of 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 to compensate for the dispersion of the corresponding optical path and compress the pulse width.

[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 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 to compensate for the dispersion reverse of the corresponding optical path.

[0021] Furthermore, 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 includes a translation base and a plurality of mutually parallel or perpendicular reflectors arranged 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.

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

[0024] 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.

[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 in 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 and fourth quadrants; 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 and third quadrants;

[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 the reflected light is incident on the first multi-pass reflection structure at an angle of 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 the reflected light is incident on the reflective mirror on the first linear translation stage, which is movable along the X-axis. 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 reflective mirror on it, and the reflected light is incident on the first output 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 the light is incident on the second multi-pass reflection structure 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 at the same angle from the negative direction of the X-axis to the positive direction of the X-axis, and the light is incident on the reflective mirror on the second linear translation stage, which is movable along the X-axis. The second linear translation stage reflects the second reflected light from the positive direction of the X-axis to the negative direction of the X-axis through the reflective mirror thereon, and the light is incident on the second output 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 enters the third multi-pass reflection structure at 2 to 10 degrees; the third reflection group B reflects the third reflected light emitted from 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 enters the reflective mirror on the third linear translation stage, which can move along the X-axis direction; the third linear translation stage reflects the third reflected light from the negative direction of the X-axis to the positive direction of the X-axis through the reflective mirror on it, and enters the third output reflective mirror.

[0033] Furthermore, 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 reflective group A includes a first reflective mirror I and a first reflective mirror II arranged perpendicular thereto, wherein the first reflective mirror I is arranged along the angle bisector of the second quadrant and the fourth quadrant;

[0035] The first reflective group B includes a first reflective mirror III and a first reflective mirror IV arranged perpendicular thereto, wherein the first reflective mirror III is arranged along the angle bisector of the first quadrant and the third quadrant;

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

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

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

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

[0040] Furthermore, 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 is provided near each multi-pass reflector structure. These holes are used to correspondingly reinstall the reflectors of the first, second, and third channels when adjusting or 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 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°.

[0045] Furthermore, 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 includes 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 composed of 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 the laser generating the incident light with the incident filter;

[0051] S1, open 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 path lengths 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 comprises 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 reflector is adjusted to increase or decrease the dispersion compensation amount, and then step S4 is executed;

[0055] If the chirped reflector assembly 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, performs 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 performs dispersion compensation and pulse width compression through a multi-pass reflection structure;

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

[0059] The present invention has the following beneficial effects compared with the prior art:

[0060] 1. The present invention provides a universal high-power attosecond light field synthesis instrument, which is designed with a small-angle, adjustable multi-pass reflection structure. The structure is compact and flexible. While ensuring the consistency of the optical path of the three channels, the number of chirped reflectors can be adjusted according to the dispersion of the incident light to change the dispersion compensation amount. 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, and improve the universality of the attosecond light field synthesizer for various broadened spectra. It solves the problem of large dispersion differences in different bands of the wide spectrum, and improves 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 added to the periphery of the multi-pass reflection structure of each channel. 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. 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. 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. 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. This ensures that the multi-pass reflection structure has good heat dissipation conditions, improves the stability of the equipment, and increases the power of the receivable light pulses, thereby increasing the output light power, and can achieve 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 mirrors and other mirrors 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. It solves the problem that the dispersion difference between different bands in a wide spectrum is large and cannot achieve the synthesis of attosecond pulses, such as the output light of a multi-stage OPA system, and realizes high-power visible light attosecond light field synthesis with controllable dispersion. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0066] Figure 2 is a structural schematic 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 an embodiment of the present invention (water cooling device omitted);

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

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

[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 optical filter; 5 - first thin fused silica wedge pair; 6 - first reflector I; 7 - first reflector II; 8 - first multi-pass reflective 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 optical filter; 15 - second thin fused silica wedge pair; 16 - second reflector I; 17 - second reflector II; 18 - second multi-pass reflective structure; 19 - second reflector III; 20 - second reflector IV; 21 - second linear translation stage; 22 - second exit beam splitter;

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

[0076] The specific technical solutions in the embodiments of the present invention will be further described below with reference to 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 optical path of the incident light on the light field synthesis base 01; 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 the 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 along the outgoing light path on the light field synthesis base 01.

[0080] The first channel, the second channel, and the third channel each include a filter, a pair of thin fused silica wedges, a multi-pass reflection structure, a linear translation stage, and multiple mirrors, which are sequentially arranged on the corresponding optical paths. The parameters of each component are adapted to the wavelength band of the corresponding optical path. The mirrors are used to change the direction of the optical path and make the optical path lengths 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 to compensate for the dispersion reverse of the corresponding optical path.

[0082] The linear translation stage includes a translation base and two perpendicularly positioned reflectors mounted on the base. These mirrors are used to adjust the lengths of corresponding optical paths, ensuring that the optical paths of the first, second, and third channels are identical, while also controlling the relative delay between the channels. The translation base has a movement accuracy of 1 nm (corresponding to a time accuracy of 6.7 attoseconds). In other embodiments of the present invention, only two linear translation stages are required to adjust the optical paths of the three channels. This allows the unmounted channel to be used as a reference, reducing 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 reflective mirror 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 reflective mirror 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 reflective mirror 23, the first exit beam splitter 12, the second exit beam splitter 22, and the third exit reflective mirror 32 are all arranged along the Y-axis.

[0086] refer to Figure 2The chirped reflector group in the multi-pass reflective 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 is provided near each multi-pass reflective structure, which is used to reinstall the reflectors of the first channel, the second channel, and the third channel when adjusting and removing 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 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 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 perpendicular to it, 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 perpendicular to it, 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 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 is incident on the reflective 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 reflective mirror thereon, and is incident on the first output 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 fused silicon wedge pair 5 for dispersion reverse compensation. Then, it 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 reflection and the amount of band dispersion compensation) to achieve dispersion compensation and pulse width compression. Then, it enters the first linear translation stage 11. By adjusting the relative position of the displacement base of the first linear translation stage 11, the optical path and phase of the first channel are controlled to be the same as those of the other channels, thereby ensuring the quality of the composite 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 reflection mirror I16 and a second reflection mirror II17 arranged perpendicularly thereto, and the second reflection mirror I16 is arranged along the angular bisector of the first quadrant and the third quadrant; the second reflection group B includes a second reflection mirror III19 and a second reflection mirror IV20 arranged perpendicularly thereto, and the second reflection mirror 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 the light is incident on the second multi-pass reflection structure 18 at a 5° angle. 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 light is incident on the reflective mirror on the second linear translation stage 21. The second linear translation stage 21 is movable along the X-axis. 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 reflective mirror thereon, and the light is incident on the second output 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 perpendicular to it, 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 perpendicular to it, 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 the light 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 the light is incident on the reflective mirror on the third linear translation stage 31. The third linear translation stage 31 can move along the X-axis direction. The third linear translation 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 reflective mirror thereon, and the light is incident on the third output reflective mirror 32.

[0095] The third reflected light is in the visible to infrared wavelength range. After being reduced by the third filter 24 to have the same energy as the first channel light, its processing method 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 an embodiment of the present invention, the reflector is a chirped reflector or a highly reflective plane mirror (depending on the actual dispersion compensation required). The highly reflective plane mirror can be a silver reflector or an aluminum reflector as needed. The highly reflective plane mirror can replace the chirped reflector when no further dispersion compensation is required. 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 chirped reflector is used to compensate for the dispersion of the input light pulse and the dispersion introduced by other transmission elements in each channel (thin fused silica wedge pairs, variable neutral density filters, and beam splitters). Its parameters are selected according to the corresponding channel to match the control bands of the three channels.

[0098] refer to Figure 3 The light field synthesis base 01 is made of aluminum. The heat dissipation device 02 includes a water-cooled heat pipe embedded within the light field synthesis base 01 and a water-cooling device connected to the water-cooled heat pipe. The water-cooled heat pipe is composed of at least three U-shaped tubes connected end to end. High-power lasers generate high levels of heat during instrument operation, which can affect the working state of various optical components. Introducing water cooling can promptly dissipate heat conducted during instrument operation, improving the stability of the device and the receivable optical pulse power, significantly reducing heat dissipation pressure.

[0099] In other embodiments of the present invention, the chirped mirror assembly in the multi-pass reflective structure can also be a one-piece bar-shaped chirped mirror. This loses the advantage of flexible adjustment of the number of chirped mirrors (adjustable dispersion compensation), but correspondingly simplifies the installation process and makes adjustment more convenient.

[0100] The synthesis method of the embodiment of the present invention comprises the following steps:

[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, open 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 temporal interference of the cross-band parts of different channels;

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

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

[0105] Generally speaking, the chirped reflectors in a multi-pass reflector structure are removed in pairs so that the corresponding outgoing light paths are parallel to the original outgoing light paths. Therefore, 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, performs 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 performs dispersion compensation and pulse width compression through a multi-pass reflection structure;

[0108] S6, combining the first reflected light, the second reflected light and the third reflected light into an outgoing light through the first outgoing beam splitter 12, the second outgoing beam splitter 22 and the third outgoing 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 Figures 1 and 2 show simulation results after changing channel parameters according to an embodiment of the present invention. A shows the light field waveform after changing the third channel pulse width (7fs, 7fs, 7fs to 7fs, 7fs, 9fs), B shows the light field waveform after changing the third channel relative intensity (1:1:1 to 1:1:3), C shows the light field waveform after changing the third channel pulse CEP (0 to pi / 4), and D shows the light field waveform after changing the third channel pulse delay (0 to 2.2fs). CEP stands for Carrier Envelope Phase.

[0111] For A, changing the channel pulse width is equivalent to changing the dispersion compensation amount of different channels; for B, the relative intensity of each channel can be adjusted using a 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 be stabilized at zero to synthesize isolated attosecond light pulses; for D, the pulse delay can be reduced to zero by adjusting the optical path length of each channel to be the same. If the optical path lengths of the three channels are different, different pulse delays will be generated.

[0112] The above content is only one embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, is 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 by: 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 provided on the light field synthesis base (01) along the outgoing light path; The first channel, the second channel, and the third channel each include a filter, a pair of thin fused silica wedges, a multi-pass reflection structure, and a plurality of reflectors arranged on the corresponding optical paths, and the parameters are 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; 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 an angle of 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 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 filter (1) and the output 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.

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 comprise 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 universal 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 translation stage; the linear translation stage has two reflective mirrors, and the movement accuracy of the translation 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 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 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 an angle of 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 reflective 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 reflective mirror thereon, and the reflected light is incident on the first output 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 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 light is incident on the second linear translation stage (21), which is movable 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, and the 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 translation 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), which 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 reflector (32).

5. A universal 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 reflector group A comprises a first reflector I (6) and a first reflector II (7) arranged perpendicular to the first reflector I (6), wherein the first reflector I (6) is arranged along the angle bisector of the second quadrant and the fourth quadrant; The first reflector group B comprises a first reflector III (9) and a first reflector IV (10) arranged perpendicular to the first reflector III (9), and the first reflector III (9) is arranged along the 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 perpendicular to the second reflector I (16), wherein the second reflector I (16) is arranged along the angle bisector of the first quadrant and the third quadrant; The second reflective group B comprises a second reflective mirror III (19) and a second reflective mirror IV (20) arranged perpendicular thereto, wherein the second reflective mirror III (19) is arranged along the angle bisector of the second quadrant and the fourth quadrant; The third reflective group A comprises a third reflective mirror I (26) and a third reflective mirror II (27) arranged perpendicular thereto, wherein the third reflective mirror I (26) is arranged along the angle bisector of the second quadrant and the fourth quadrant; The third reflective group B comprises a third reflective mirror III (29) and a third reflective mirror IV (30) arranged perpendicularly thereto. The third reflective mirror 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 includes 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; On the light field synthesis base (01), a row of threaded mounting holes parallel to the chirped reflector group is provided near each multi-pass reflective 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 universal 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 spacing between two adjacent chirped reflectors is 5 mm; the reflectors of the first channel, the second channel and the third channel allow the corresponding light beams to be incident on the corresponding chirped reflector group at 5°.

8. The universal 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 are as follows: S0, manufacturing the universal high-power attosecond light field synthesis instrument according to any one of claims 1 to 8, aligning a laser generating incident light with the incident filter (1); S1, open 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 comprises 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 reflector is adjusted to increase or decrease the dispersion compensation amount, and then step S4 is executed; If the chirped reflector assembly is a bar-shaped chirped reflector, directly execute step S4; S4, splitting the incident light into a first reflected light, a second reflected light and a third reflected light by the first incident beam splitter (3), the second incident beam splitter (13) and the third incident reflecting mirror (23); S5, performing dispersion reverse compensation on the first reflected light, the second reflected light, and the third reflected light respectively through the thin fused silica wedge pair, and performing dispersion compensation and pulse width compression through the multi-pass reflection structure; S6, combining the first reflected light, the second reflected light and the third reflected light into outgoing light through the first outgoing beam splitter (12), the second outgoing beam splitter (22) and the third outgoing reflecting mirror (32) to obtain attosecond light pulses.

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