A device for generating multiple sequential beams of light based on the tilting of the pulse leading edge.

Abstract

This invention discloses a device for generating multiple temporal beams based on pulse leading-edge tilting, relating to the field of ultrafast imaging technology. The device includes: a long elliptical beam generation system for generating a long elliptical beam; a leading-edge tilting pulse generation system for generating a leading-edge tilted pulse based on the long elliptical beam output by the long elliptical beam generation system; and a temporal beam generation system for splitting the leading-edge tilted pulse into multiple temporal beams using a multi-aperture aperture. This invention utilizes pulse leading-edge tilting technology to generate multiple temporal beams, which, when interacted with ultrafast events, produce an interferogram. The pulse leading-edge tilting technique combined with spatial coordinate transformation technology can construct a spatiotemporally coupled light field with linear spatial and temporal correlation. Fourier filtering technology can then be used to separate the images of each frame. By selecting a suitable pinhole array, the number of frames can be flexibly adjusted. The device features a simple and compact structure and high reliability.

Description

Technical Field

[0001] This invention relates to the field of ultrafast imaging technology, and more specifically to a device for generating multiple sequential beams of light based on the tilting of the pulse leading edge. Background Technology

[0002] Ultrafast imaging is a hot research topic, particularly suitable for extremely short-lived processes that are difficult to detect using conventional methods. Typical applications include the real-time capture of transient phenomena such as laser-plasma interactions and photosynthesis. Existing ultrafast imaging techniques include spectral coding, frequency-domain holography, spatial coding, and compressed ultrafast imaging, among which pump-probe imaging is widely used due to its simplicity and reliability. Furthermore, spectral coding techniques for spatiotemporal information have also become a research focus.

[0003] In ultrafast imaging techniques, pump-probe imaging is simple and reliable, while another more specialized type is spectral encoding of spatiotemporal information. Before spectral encoding, temporal encoding is required, which involves using multiple pulses with different time delays—i.e., sequential light—to illuminate the ultrafast process at different azimuth angles. Prior to spectral encoding, multiple pulses with different time delays need to be generated through temporal encoding to construct a sequential beam to illuminate and detect the ultrafast process. To achieve this, pulse leading-edge tilting techniques have become an effective method. By controlling the pulse leading edge, multiple sequential beams are generated, which can be used to capture and image ultrafast events.

[0004] Currently, temporal beam generation methods based on pulse leading-edge tilting techniques still have certain limitations, mainly reflected in high system complexity, insufficient structural compactness, and difficulty in image frame separation. Therefore, how to effectively and efficiently generate multiple temporal beams and combine them with spatial coordinate transformation techniques to achieve efficient image separation in ultrafast imaging is a significant challenge in current technology. Summary of the Invention

[0005] The purpose of this invention is to provide a device for generating multiple temporal beams based on the pulse leading edge, for ultrafast imaging applications of ultrafast objects. This device can efficiently generate multiple temporal beams that interact with ultrafast objects, thereby achieving ultrafast imaging. By combining pulse leading edge tilting technology with spatial coordinate transformation technology, this device can flexibly control the generation of multiple temporal beams and achieve efficient image separation.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a device for generating multiple sequential beams of light based on pulse leading edge tilt, comprising:

[0008] Long elliptical beam generation system, used to generate long elliptical beams;

[0009] A leading-edge tilted pulse generation system is used to generate leading-edge tilted pulses based on the long elliptical beam output by a long elliptical beam generation system.

[0010] A timing beam generation system is used to split a leading-edge tilted pulse into multiple timing beams using a multi-aperture aperture.

[0011] As a further aspect of the present invention, the elongated elliptical beam generating system includes a first convex lens, a second convex lens, a first cylindrical lens, and a second cylindrical lens, used to convert the Gaussian pulse entering the elongated elliptical beam generating system into an elongated elliptical beam. Specifically, the Gaussian pulse passes sequentially through the first convex lens, the second convex lens, the first cylindrical lens, and the second cylindrical lens of the elongated elliptical beam generating system to form an elongated elliptical beam.

[0012] As a further aspect of the present invention, a fiber femtosecond laser generates a Gaussian pulse that enters the elongated elliptical beam generation system, with a wavelength of 1030 nm and a pulse width on the order of hundreds of femtoseconds.

[0013] As a further aspect of the present invention, the multi-beam timing light is a multi-beam laser pulse signal output by a timing light generation system. The timing beams have different time delays, and the generated multi-beam timing light can be used to interact with ultrafast events.

[0014] As a further embodiment of the present invention, in the long elliptical beam generating system, the focal length of the first convex lens is 200mm, the focal length of the second convex lens is 50mm, the focal length of the first cylindrical lens is 50mm, and the focal length of the second cylindrical lens is 400mm.

[0015] As a further embodiment of the present invention, the mirror surfaces of the first convex lens and the second convex lens are parallel to each other and the distance between them is 250mm. The convex surface of the first convex lens is opposite to the direction of the beam propagation, and the convex surface of the second convex lens is in the same direction as the direction of the beam propagation.

[0016] The mirror surfaces of the first cylindrical lens and the second cylindrical lens are parallel to each other, and the first cylindrical lens and the second cylindrical lens are 450mm apart. The angle between the x and y axes of the first cylindrical lens and the x and y axes of the second cylindrical lens is 0. The convex surface of the first cylindrical lens is opposite to the direction of the beam, and the convex surface of the second cylindrical lens is in the same direction as the direction of the beam.

[0017] As a further aspect of the present invention, the leading-edge tilt pulse generation system includes an equilateral prism, the equilateral prism being made of H-ZF13 material and having dimensions of 40×40×40mm. 3 The elongated elliptical beam is incident horizontally onto an equilateral prism at a predetermined incident angle, causing the pulse leading edge of the elongated elliptical beam to tilt.

[0018] As a further aspect of the present invention, the timing beam generation system includes a small aperture array with an aperture size of 40×50mm.2 The rectangular aperture has holes arranged linearly, with the central hole located at the intersection of the diagonals of the rectangular aperture. The holes have a diameter of 0.5 mm and a spacing of 3 mm, arranged sequentially along the horizontal direction.

[0019] In the above technical solution, the device for generating multiple sequential beams of light based on the tilting of the pulse leading edge provided by the present invention has the following beneficial effects:

[0020] This invention relates to a device for generating multiple temporal beams based on pulse leading-edge tilting. After generating multiple temporal beams using pulse leading-edge tilting technology, these beams interact with ultrafast events to obtain an interferogram. The pulse leading-edge tilting technique, combined with spatial coordinate transformation, constructs a spatiotemporally coupled optical field with linear spatial and temporal correlation. Fourier filtering then separates the individual frames. The number of frames can be flexibly adjusted by selecting a suitable pinhole array. The device is simple, compact, and highly reliable. Furthermore, by using a pseudo-random coded mask instead of a pinhole array, it is expected to achieve continuous scanning imaging in two-dimensional space and one-dimensional time. The multiple temporal beams generated by this invention can interfere with ultrafast events to obtain an interferogram. A spatiotemporally coupled optical field with linear spatial and temporal correlation is then constructed as the coherent shutter for a single ultrafast imaging session. This spatiotemporal correlation enables time-space frequency encoding between multiple images. Fourier filtering of the acquired images allows for the separation of individual frames, thus achieving ultrafast imaging. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0022] Figure 1 This is a schematic diagram of the structure of a device for generating multiple sequential beams of light based on the tilting of the pulse leading edge according to the present invention.

[0023] Figure 2 This is a schematic diagram of the structure of the elongated elliptical beam generation system in the device for generating multiple sequential beams based on the tilting of the pulse leading edge according to the present invention.

[0024] Figure 3 This is a schematic diagram of the leading edge tilt pulse generation system in the device for generating multiple sequential beams of light based on the tilting of the leading edge of a pulse according to the present invention.

[0025] Figure 4 This is a schematic diagram of the timing beam generation system in the device for generating multiple timing beams based on the tilting of the pulse leading edge according to the present invention.

[0026] Figure label:

[0027] 11. Long elliptical beam generation system; 12. Leading edge tilt pulse generation system; 13. Timing beam generation system; 21. First convex lens; 22. Second convex lens; 23. First cylindrical lens; 24. Second cylindrical lens; 31. Equilateral prism; 41. Pinhole array aperture. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings.

[0029] Current time-series beam generation methods based on pulse leading-edge tilting technology still have certain limitations, mainly in terms of high system complexity, insufficient structural compactness, and difficulty in image frame separation. The purpose of this invention is to provide a device for generating multiple time-series beams based on pulse leading-edge tilting for ultrafast imaging applications of ultrafast objects. This device can efficiently generate multiple time-series beams that interact with ultrafast objects, thereby achieving ultrafast imaging. By combining pulse leading-edge tilting technology with spatial coordinate transformation technology, this device can flexibly control the generation of multiple time-series beams and achieve efficient image separation.

[0030] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0031] like Figure 1 As shown, one embodiment of the present invention provides an apparatus for generating multiple sequential beams of light based on pulse leading edge tilt, the apparatus comprising:

[0032] Long elliptical beam generation system 11, used to generate long elliptical beams;

[0033] The leading-edge tilting pulse generation system 12 is used to generate leading-edge tilting pulses based on the long elliptical beam output by the long elliptical beam generation system 11.

[0034] The timing beam generation system 13 is used to split a leading-edge tilted pulse into multiple timing beams through a multi-aperture aperture.

[0035] In this embodiment, multiple time-series beams are generated using pulse leading edge tilting technology and then interacted with ultrafast events to obtain an interferogram. The pulse leading edge tilting technology combined with spatial coordinate transformation technology can be used to construct a spatiotemporally coupled light field with linear spatial and temporal correlation. Then, Fourier filtering technology can be used to separate the images of each frame.

[0036] Specifically, in this embodiment, the femtosecond Gaussian pulse first enters the elongated elliptical beam generation system 11, generating an elongated elliptical beam. This beam then passes through the leading-edge tilting pulse generation system 12, causing the leading edge of the elongated elliptical beam to tilt. It then passes through the timing beam generation system 13, where it first passes through a customized pinhole array aperture 41, with the apertures arranged linearly. Multiple timing beams are then generated through the timing beam generation system.

[0037] In this embodiment, the multiple time-sequential beams refer to the multiple laser pulse signals output by the time-sequential beam generation system, with each beam having a different time delay. The generated multiple time-sequential beams can be used to interact with ultrafast events.

[0038] In this embodiment, the device for generating multiple sequential beams based on the tilted pulse leading edge is achieved by tilting the leading edge of an elongated elliptical beam and then generating multiple sequential beams through a rectangular aperture. Specifically, in this embodiment, a fiber femtosecond laser is used to generate Gaussian pulses that enter the elongated elliptical beam generation system 11, with a wavelength of 1030 nm and a pulse width on the order of hundreds of femtoseconds.

[0039] It should be noted that, in actual implementation, the laser can be replaced with other lasers according to actual needs.

[0040] The multiple time-series beams generated by this invention can interfere with ultrafast events, such as plasma and ultrafast rotating light fields. After obtaining the interference pattern, a spatiotemporally coupled light field with linear spatial and temporal correlation is constructed as a coherent shutter for a single ultrafast imaging operation. Utilizing this spatiotemporal correlation, time-space frequency encoding between multiple images can be achieved. The acquired images can be separated into individual frames using Fourier filtering techniques, thereby realizing ultrafast imaging.

[0041] In this embodiment, see Figure 2 As shown, the elongated elliptical beam generation system 11 includes a first convex lens 21, a second convex lens 22, a first cylindrical lens 23, and a second cylindrical lens 24, used to convert Gaussian pulses entering the elongated elliptical beam generation system 11 into elongated elliptical beams. The Gaussian pulses pass sequentially through the first convex lens 21, the second convex lens 22, the first cylindrical lens 23, and the second cylindrical lens 24 of the elongated elliptical beam generation system 11 to form an elongated elliptical beam.

[0042] In the long elliptical beam generation system 11, the focal length of the first convex lens 21 is 200mm, the focal length of the second convex lens 22 is 50mm, the focal length of the first cylindrical lens 23 is 50mm, and the focal length of the second cylindrical lens 24 is 400mm. A 1030nm Gaussian laser pulse with a diameter of 6mm generated by a femtosecond laser passes through the above components in sequence, and the incident mode is normal incidence.

[0043] In this embodiment, the mirror surfaces of the first convex lens 21 and the second convex lens 22 are parallel to each other and are 250mm apart. The convex surface of the first convex lens 21 is opposite to the direction of the beam propagation, while the convex surface of the second convex lens 22 is in the same direction as the beam propagation. The mirror surfaces of the first cylindrical lens 23 and the second cylindrical lens 24 are parallel to each other and are 450mm apart. The x and y axes of the first cylindrical lens 23 and the x and y axes of the second cylindrical lens 24 make an angle of 0°. The convex surface of the first cylindrical lens 23 is opposite to the direction of the beam propagation, while the convex surface of the second cylindrical lens 24 is in the same direction as the beam propagation.

[0044] In this embodiment, see Figure 3 As shown, the leading-edge tilting pulse generation system 12 includes an equilateral prism 31, which is made of H-ZF13 and has dimensions of 40×40×40mm. 3 A pulse with a leading edge tilt is incident horizontally onto an equilateral prism 31 at an incident angle calculated from the minimum deflection angle of the prism.

[0045] Among them, the minimum deviation angle δ is calculated. m The formula is:

[0046]

[0047] In the formula, n is the refractive index of the prism, the equilateral prism 31 is made of H-ZF13 with a refractive index of 1.755, and α is the vertex angle, which is the equilateral prism 31 here.

[0048] In this embodiment, the incident angle i is calculated. min The formula is:

[0049]

[0050] Specifically, after the elongated elliptical beam passes through the equilateral prism 31, the leading edge of the pulse is tilted, and the horizontal position delay is calculated according to the incident angle.

[0051] In this embodiment, see Figure 4 As shown, the timing beam generation system 13 includes a small aperture array 41 with a size of 40×50mm. 2 The rectangular aperture has holes arranged linearly, with the central hole located at the intersection of the diagonals of the rectangular aperture. The holes have a diameter of 0.5 mm and a spacing of 3 mm, arranged sequentially along the horizontal direction.

[0052] There are 5 linear apertures. The elongated elliptical pulse is split into 5 sequential beams after passing through the aperture array 41. It should be noted that the aperture spacing can be flexibly set according to experimental needs to generate the required timing and number of beams.

[0053] This invention relates to a device for generating multiple temporal beams based on pulse leading-edge tilting. After generating multiple temporal beams using pulse leading-edge tilting technology, these beams interact with ultrafast events to obtain an interferogram. The pulse leading-edge tilting technique, combined with spatial coordinate transformation, constructs a spatiotemporally coupled optical field with linear spatial and temporal correlation. Fourier filtering then separates the individual frames. The number of frames can be flexibly adjusted by selecting a suitable pinhole array. The device is simple, compact, and highly reliable. Furthermore, by using a pseudo-random coded mask instead of a pinhole array, it is expected to achieve continuous scanning imaging in two-dimensional space and one-dimensional time. The multiple temporal beams generated by this invention can interfere with ultrafast events to obtain an interferogram. A spatiotemporally coupled optical field with linear spatial and temporal correlation is then constructed as the coherent shutter for a single ultrafast imaging session. This spatiotemporal correlation enables time-space frequency encoding between multiple images. Fourier filtering of the acquired images allows for the separation of individual frames, thus achieving ultrafast imaging.

[0054] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “the,” and “the” used in this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0055] It should be understood that although the terms first, second, third, etc., may be used in this invention to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of this invention, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for generating multiple sequential beams of light based on the tilting of the pulse leading edge, characterized in that, include: An elliptical beam generation system is used to generate an elliptical beam; wherein the elliptical beam generation system includes a first convex lens, a second convex lens, a first cylindrical lens, and a second cylindrical lens, used to convert Gaussian pulses entering the elliptical beam generation system into elliptical beams. A leading-edge tilted pulse generation system is used to generate a leading-edge tilted pulse based on an elongated elliptical beam output by an elongated elliptical beam generation system; wherein, the leading-edge tilted pulse generation system includes an equilateral prism, and the elongated elliptical beam is horizontally incident on the equilateral prism at a predetermined incident angle, so that the elongated elliptical beam generates a pulse with a leading edge tilted. A timing beam generation system is used to split a leading-edge tilted pulse into multiple timing beams using a multi-aperture aperture; wherein, the timing beam generation system includes a pinhole array aperture, the apertures of which are linearly arranged, the central aperture being located at the intersection of the diagonals of a rectangular aperture, and arranged sequentially along the horizontal direction; The multiple time-series beams are multiple laser pulse signals output by the time-series beam generation system. The time-series beams have different time delays, and the generated multiple time-series beams are used in conjunction with ultrafast events. The mirror surfaces of the first convex lens and the second convex lens are parallel to each other. The convex surface of the first convex lens is opposite to the direction of the beam's propagation, while the convex surface of the second convex lens is in the same direction as the beam's propagation. The mirror surfaces of the first cylindrical lens and the second cylindrical lens are parallel to each other. The angle between the x and y axes of the first cylindrical lens and the x and y axes of the second cylindrical lens is 0. The convex surface of the first cylindrical lens is opposite to the direction of the beam's propagation, while the convex surface of the second cylindrical lens is in the same direction as the beam's propagation.

2. The device for generating multiple sequential beams of light based on pulse leading edge tilting according to claim 1, characterized in that, The device uses a fiber femtosecond laser to generate Gaussian pulses that enter the elongated elliptical beam generation system, with pulse widths on the order of hundreds of femtoseconds.

3. The device for generating multiple sequential beams of light based on pulse leading edge tilting according to claim 2, characterized in that, In the long elliptical beam generation system, the focal length of the first convex lens is 200mm, the focal length of the second convex lens is 50mm, the focal length of the first cylindrical lens is 50mm, and the focal length of the second cylindrical lens is 400mm.

4. The device for generating multiple sequential beams of light based on pulse leading edge tilting according to claim 3, characterized in that, The aperture is a rectangular aperture.

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