A method for generating an ultrastrong ultrafast pulsed light spring

Abstract

The application discloses a method for generating an ultrastrong and ultrafast pulsed optical spring and relates to the technical field of ultrastrong and ultrafast pulsed optical regulation.The method forms a 4f system by an ultrastrong and ultrafast femtosecond pulsed laser 1, a first blazed grating 2, a first off-axis parabolic mirror 3, a vortex array 4, a second blazed grating 5, a second off-axis parabolic mirror 6 and a strong-field optical spring 7; the ultrastrong and ultrafast femtosecond pulsed laser 1 is subjected to first Fourier transform through the first blazed grating 2 and the first off-axis parabolic mirror 3; the strong-field optical spring 7 is generated through the vortex array 4, the second blazed grating 5 and the second off-axis parabolic mirror 6 for second Fourier transform.The method is based on a classical theory, has low experimental difficulty, the vortex phase plate is easy to prepare, has small dispersion in the generation process, has the characteristics of strong practicability and innovation, and the strong-field optical spring light can meet the basic requirements of interaction experiments with plasma and other substances, thereby providing a pioneering method for opening up the application prospect of the strong-field optical spring.

Description

Technical Field

[0001] This invention relates to the field of ultra-intense and ultra-fast pulsed light control technology, specifically to a method for generating an ultra-intense and ultra-fast pulsed light spring. Background Technology

[0002] In the field of ultraintense and ultrafast pulsed light, the control and measurement of spatiotemporal coupling is a research hotspot. Properly controlled spatiotemporally coupled pulsed light holds promise for assisting a series of cutting-edge experiments in this field. One type of spatiotemporally coupled pulsed light that has been extensively studied is the spatiotemporal vortex light, which not only possesses a phase singularity in the spatial domain but also carries transverse orbital angular momentum. Another type of spatiotemporally coupled pulsed light that urgently needs further study is the optical spring. Besides sharing the same characteristics and advantages as the spatiotemporal vortex light, its phase and intensity distributions are both helical, allowing it to encode both the transverse orbital angular momentum carried by the light and exhibit different pitches. These intriguing optical properties give optical springs considerable application potential in areas such as particle rotation and manipulation, optical information encoding, and laser-matter interactions.

[0003] Several methods for generating optical springs have been proposed. The simplest approach involves irradiating an ultrashort pulse onto a vortex phase plate whose thickness varies with orientation. However, this method is limited by manufacturing technology, making it difficult to produce vortex phase plates that meet the required specifications. Furthermore, the transmission of ultra-intense, ultra-fast pulsed light through such a vortex phase plate results in significant dispersion, thus disrupting the generation of the optical spring. Additionally, the optical properties of the optical spring generated using this method cannot be independently controlled. Another approach involves generating the optical spring through an interference optical path and a liquid crystal spatial light modulator. However, the optical spring generated by this method has a large pitch, making it unsuitable for the application of ultra-intense, ultra-fast pulsed light.

[0004] Each of these solutions has its own drawbacks and limitations, either requiring stringent experimental conditions or failing to meet the application requirements in the field of ultra-intense and ultra-fast pulsed light.

[0005] Therefore, a scheme for generating optical springs based on ultra-intense and ultra-fast femtosecond pulsed lasers urgently needs to be proposed to meet the application requirements in the field of laser-matter interaction, while also satisfying technical requirements such as weak dispersion, ease of processing, and small pitch. Summary of the Invention

[0006] The purpose of this invention is to address the deficiencies and shortcomings of existing technologies by proposing an ultra-strong and ultra-fast pulsed light modulation technology, specifically a method for generating an ultra-strong and ultra-fast pulsed light spring.

[0007] A method for generating an ultra-intense, ultra-fast pulsed optical spring involves loading different vortex phases at different frequency positions of a strong-field femtosecond pulsed laser in the space-frequency domain, thereby generating a strong-field optical spring in the space-time domain. Further, a Fourier transform is performed on the strong-field femtosecond pulsed laser using a blazed grating and an off-axis parabolic mirror, causing different spectral components of the incident pulse to be positioned differently in the space-frequency domain. Then, a reflective vortex array is used to load vortex phases with different topological charges onto the sub-components of the ultra-intense, ultra-fast femtosecond pulsed laser at different frequencies in the space-frequency domain.

[0008] The reflective vortex array can be customized to meet specific requirements and can simultaneously load any number of different topological charges. Furthermore, as it is a reflective diffraction device, it does not produce dispersion, resulting in a high-quality strong-field optical spring.

[0009] The strong-field femtosecond pulsed laser is a pulsed light with a pulse width of 30 fs generated by a mode-locked femtosecond laser with a center wavelength of 800 nm.

[0010] The high-field femtosecond pulsed laser first undergoes a Fourier transform through a first set of blazed gratings and off-axis parabolic mirrors, then is incident on a reflective vortex array at different positions in the space-frequency domain to load different vortex phases, and finally undergoes a second Fourier transform through a second set of blazed gratings and off-axis parabolic mirrors, thereby generating a high-field optical spring in the space-time domain.

[0011] As described above, the technical problem actually solved by this invention can be summarized as follows: in ultra-strong and ultra-fast pulsed light modulation technology, the reflective vortex array can be customized according to requirements and can simultaneously load any different topological charges. Furthermore, because it is a reflective diffraction device, it does not produce dispersion, ultimately resulting in a high-quality strong-field light spring.

[0012] The beneficial effects of this invention are as follows: The method for generating strong-field optical springs exhibits low dispersion during the generation process, making it suitable for strong-field femtosecond pulsed lasers rather than ordinary weak light. The generated strong-field optical springs possess extremely high light intensity, meeting the basic requirements for conducting experiments involving interactions with plasma and other matter, and demonstrating novel and unique application prospects. The reflective vortex array used in this method is experimentally easy to fabricate and has low processing difficulty, and the pitch of the generated strong-field optical springs is adjustable. This method can also meet the light field control requirements in other fields of strong laser-matter interaction. Attached Figure Description

[0013] Figure 1 This is a schematic block diagram illustrating the principle of a method for generating an ultra-strong and ultra-fast pulsed light spring according to the present invention.

[0014] Figure 2 This is a spectrum of a strong-field femtosecond pulsed laser from an embodiment of the present invention;

[0015] Figure 3 The reflective vortex array used in the embodiments of the present invention;

[0016] Figure 4 This is a two-dimensional structural diagram of a strong field optical spring provided in an embodiment of the present invention;

[0017] Figure 5 This is a three-dimensional structural diagram of a strong field light spring provided in an embodiment of the present invention. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] A method for generating an ultra-strong and ultra-fast pulsed light spring (as attached) Figure 1 As shown, a 4f system is formed by an ultra-intense and ultra-fast femtosecond pulsed laser 1, a first blazed grating 2, a first off-axis parabolic mirror 3, a vortex array 4, a second blazed grating 5, a second off-axis parabolic mirror 6, and a strong field optical spring 7.

[0020] The first blazed grating 2 is placed on the front focal plane of the first off-axis parabolic mirror 3, and the second blazed grating 5 is placed on the rear focal plane of the second off-axis parabolic mirror 6.

[0021] The distance between the first off-axis parabolic mirror 3 and the second off-axis parabolic mirror 6 is twice the focal length of the off-axis parabolic mirror.

[0022] The ultra-intense and ultra-fast femtosecond pulsed laser 1 undergoes a first Fourier transform after passing through the first blazed grating 2 and the first off-axis parabolic mirror 3;

[0023] A second Fourier transform is performed through the vortex array 4, the second blazed grating 5, and the second off-axis parabolic mirror 6 to generate a strong field light spring 7.

[0024] Different vortex phases were applied to an ultra-intense, ultrafast femtosecond pulse laser at different locations in the space-frequency domain.

[0025] Example: A method for generating an ultra-strong and ultra-fast pulsed optical spring (as shown in the attached document). Figure 2 As shown), the vortex array 4 is a reflective type that does not produce dispersion and has a uniform thickness that is easy to process;

[0026] In the space-frequency domain, vortex phases with different topological charges are loaded onto sub-components of ultra-intense and ultrafast femtosecond pulsed lasers of different frequencies.

[0027] The ultra-intense and ultra-fast femtosecond pulsed laser 1 is generated by a mode-locked femtosecond laser, with a pulse width of 30–100 fs, a center wavelength of 600–1000 nm, and an arbitrary spot radius.

[0028] The optimal values ​​are: pulse width of 30 fs, center frequency of 800 nm, and spot radius of 3 mm.

[0029] Implementation examples (as shown in the attached figures) Figure 1 To be continued Figure 5 As shown, the ultra-intense and ultra-fast femtosecond pulsed laser 1 undergoes a first Fourier transform after passing through the first blazed grating 2 and the first off-axis parabolic mirror 3.

[0030] Furthermore, the reflective vortex array 4 loads different vortex phases at different locations in the space-frequency domain.

[0031] After loading different vortex phases at different locations in the space-frequency domain, the ultra-intense and ultra-fast femtosecond pulse laser 1 undergoes a second Fourier transform through the second blazed grating 5 and the second off-axis parabolic mirror 6, and synthesizes a strong field light spring 7 in the far field.

[0032] The phase distribution on the reflective vortex array 4 can be represented by M(r, θ) (as shown in the appendix). Figure 3 (As shown).

[0033] The above two Fourier transform processes are represented by the following equation:

[0034] E(r, θ) = F -1 {M(r, θ)·F{E0(r, θ)}}

[0035] Where (r, θ) are polar coordinates in the space-frequency domain, E0(r, θ) is the optical field distribution of the ultra-intense and ultrafast femtosecond pulsed laser 1, E(r, θ) is the optical field distribution of the strong field spring 7, and F and F -1 These represent the Fourier transform and the inverse Fourier transform, respectively.

[0036] In this embodiment, the strong-field optical spring 7 is generated by a strong-field femtosecond pulsed laser, exhibiting extremely high light intensity and energy. Two-dimensional and three-dimensional optical field structure diagrams show that it not only possesses controllable lateral orbital angular momentum (as shown in the attached diagram)... Figure 4 As shown), and both the phase and intensity distributions are spiral structures (as shown in the attached figure). Figure 5 As shown in the figure, this allows it to both encode the transverse orbital angular momentum carried by light and exhibit different pitches.

[0037] In summary, the optical properties of this method give strong-field optical springs unique application potential in areas such as particle rotation and manipulation, optical information encoding, and the interaction between strong lasers and matter. This scheme for generating strong-field optical springs using strong lasers provides a pioneering approach to expanding the application prospects of strong-field optical springs in fields such as the interaction between strong lasers and plasmas. Furthermore, this method is based on classical theory, has relatively low experimental difficulty, the vortex phase plate is easy to fabricate, and the dispersion during generation is small, exhibiting strong practicality and innovation, and can also be applied to other optical fields.

Claims

1. A method for generating an ultra-strong and ultra-fast pulsed optical spring, characterized in that: A 4f system is formed by an ultra-intense and ultra-fast femtosecond pulsed laser (1), a first blazed grating (2), a first off-axis parabolic mirror (3), a vortex array (4), a second blazed grating (5), a second off-axis parabolic mirror (6), and a strong field optical spring (7); The first blazed grating (2) is placed on the front focal plane of the first off-axis parabolic mirror (3), and the second blazed grating (5) is placed on the rear focal plane of the second off-axis parabolic mirror (6). The distance between the first off-axis parabolic mirror (3) and the second off-axis parabolic mirror (6) is twice the focal length of the off-axis parabolic mirror; The ultra-intense and ultra-fast femtosecond pulsed laser (1) undergoes a first Fourier transform after passing through the first blazed grating (2) and the first off-axis parabolic mirror (3); A second Fourier transform is performed through a vortex array (4), a second blazed grating (5), and a second off-axis parabolic mirror (6) to generate a strong field optical spring (7). Different vortex phases were applied to an ultra-intense, ultra-fast femtosecond pulse laser (1) at different locations in the space-frequency domain.

2. The method for generating an ultra-strong and ultra-fast pulsed optical spring as described in claim 1, characterized in that: The vortex array (4) is a reflective type that does not produce dispersion and has a uniform thickness that is easy to process; In the space-frequency domain, vortex phases with different topological charges are loaded onto sub-components of ultra-intense and ultrafast femtosecond pulsed lasers of different frequencies.

3. The method for generating an ultra-strong and ultra-fast pulsed optical spring as described in claim 1, characterized in that: The ultra-intense and ultra-fast femtosecond pulsed laser (1) has a pulse width of 30~100fs, a center wavelength of 600~1000nm, and an arbitrary spot radius.

4. The method for generating an ultra-strong and ultra-fast pulsed optical spring as described in claim 3, characterized in that: The ultra-intense and ultra-fast femtosecond pulsed laser (1) has a pulse width of 30 fs, a center wavelength of 800 nm, and a spot radius of 3 mm.

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