Wideband tunable optical parametric chirped pulse amplification system based on soliton self-frequency shift

Abstract

The invention relates to a wideband tunable optical parametric chirped pulse amplification system based on soliton self-frequency shift. Stretch soliton pulse laser generated by a pulsed laser is transmitted as a seed signal to an all-fiber chirped pulse amplification system composed of a stretcher, an amplifier and a compressor. Then the ultrashort pulse laser is outputted into an optical fiber frequency shift system composed of two different types of nonlinear fiber cascade structures. The 2-10mum wideband tunable ultrashort pulse laser generated by the optical fiber frequency shift system is outputted to a crystal of BaGa2GeSe6 structure, the crystal is connected with a laser source for matching the phase of the tunable ultrashort pulse laser and the wideband tunable mid-infrared ultrashort laser is outputted through the crystal. The generation of super-continuum spectrum laser in the optical fiber laser system and the high-energy laser system can be effectively suppressed and the energy conversion efficiency of the seed signal in the optical parametric chirped pulse amplification system can be greatly improved.

Description

technical field [0001] The invention relates to a mid-infrared laser generation system, specifically a broadband tunable optical parametric chirped pulse amplification system based on soliton self-frequency shift. Background technique [0002] In recent years, with the rapid development of laser technology, mid-infrared ultrashort pulses in the 2-10 μm band have been widely used in medical technology, ultrashort spectroscopy, national defense, and material processing due to their ultrashort pulse width and ultrahigh peak power. The field has distinctive application requirements and has attracted widespread attention. In the field of national defense and military affairs, the 2-10 μm mid-infrared laser contains multiple atmospheric "transparent windows", and also covers the response wavelength of most military infrared detectors (mercury cadmium telluride, indium gallium arsenic, lead sulfide, etc.), so , the mid-infrared laser source located in this wavelength region has ex...

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Problems solved by technology

[0012] (1) The pulse energy and average power of the obtained ultrashort pulse laser are low;

[0013] (2) Double-clad thulium-doped fiber is used as the frequency-shifting fiber, and the Raman conversion efficiency is high, but the tunable range of the obtained ultrashort pulse laser is narrow

[0016] (1) The design of the space structure makes the overall structure complex, and the loss during the transmission of a large amount of space light is relatively large

[0017] (2) Due to the nonlinear crystal, the pulse energy output by the OPCPA system is low, and it cannot achieve wide-range wavelength tuning in the mid-infrared band

[0018] In summary, the tuning range of the signal light source in the laser system limits the substantial improvement in the tuning range of the mid-infrared broadband tunable ultrashort pulse laser

At the same time, the nonlinear crystal in mid-infrared OPCPA is also a key factor restricting the development of high-energy mid-infrared ultrafast pulses. Traditional long-wave nonlinear crystals such as: AgGaS 2 , ZnGeP 2 , AgGaSe 2 There are defects such as large thermal expansion anisotropy, low thermal conductivity, low damage threshold, and difficult crystal growth, which make it difficult to further improve laser energy and conversion efficiency.

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