Optical pulse control method and system based on multi-frequency acousto-optic modulation and grating diffraction

Abstract

The invention belongs to the technical field of pulsed laser control, in particular to a method and system for light pulse control based on multi-frequency acousto-optic modulation and grating diffraction. The method of the present invention includes: performing multi-angle Bragg deflection on the pulsed light input through multi-frequency acousto-optic modulation, making it propagate along multiple delay lines in parallel, using a large-area grating to realize reverse diffraction on all delay lines at the same time, and again passing the acousto-optic The modulator, which ultimately forms a shaped light pulse output in a single spatial mode. The invention controls the amplitude, phase and delay of the sub-pulse through radio frequency signal programming, can generate coherent optical waveforms with nearly terahertz modulation bandwidth and stable waveform, and can be used to precisely regulate the movement of atoms and molecules. The system of the invention includes: a radio frequency signal encoding module, an acousto-optic modulation module, an optical lens system, a grating module, and a frequency stabilization optical system monitoring module; the invention has important application prospects in the fields of laser cooling, atomic interference, and laser isotope separation.

Description

technical field [0001] The invention belongs to the technical field of pulse laser control, and in particular relates to a method and system for light pulse control. Background technique [0002] Optical pulse shaping (that is, optical pulse modulation) technology plays an important role in high-precision spectroscopy research and coherent quantum modulation. In the field of ultrafast optics, multidimensional coherent spectroscopy (MDCS) reveals the coherent dynamics of samples using multi-pulse excitation and coherent detection. MDCS technology requires a phase-stable multi-channel tunable optical delay, and its optical realization under ultrafast laser is technically challenging. For example, in 2003 and 2007, Chinese scientist Tian Peifang and American scientist Patrick F. Tekavec used Fourier Transform Pulse Shaping (FTPS) and interferometry to study multidimensional coherent spectroscopy under optical pulses. For high-resolution nonlinear spectroscopy with delays abov...

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Problems solved by technology

[0006] 1. The interferometry has already determined the maximum number of separable sub-pulses when the experimental optical path is built, and the delay between each pulse is fixed, and the delay cannot be quickly programmed and adjusted. Strictly speaking, it does not belong to the pulse shaping technology. ;

[0007] 2. The maximum length of the delay line of the acousto-optic programmable dispersion filter is limited by its crystal size. Currently, such devices on the market generally only provide a delay of less than 10 ps;

[0008] 3. Fourier transform pulse shaping technology uses its frequency domain component to split light, so it is not suitable for narrow bandwidth laser

However, its spatial wavefront division method itself will affect the single-mode quality and coupling efficiency of its output, especially for the generation of low duty cycle isolated pulses, etc.

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