A device used for generating high efficiency narrow linewidth intermediate infrared laser and a method

Abstract

The invention provides a device used for generating high efficiency narrow linewidth intermediate infrared laser and a method. The device comprises a pumping source, an OPO and two stages of OPAs. The device also comprises a coupling lens used for making idler frequency light and pumping light coincide and converge in a nonlinear crystal, a dichroic mirror used for separating signal light and the idler frequency light, and a dichroic mirror used for separating the idler frequency light and the pumping light. The invention also provides the method of obtaining narrow linewidth intermediate infrared laser output without inserting a linewidth controller in the cavity of the OPO. The method is characterized by adjusting the pumping spot size of crystals to control the divergence angle thereof, applying proper pumping power to obtain narrow linewidth seed light output, selecting the proper pumping power and pumping spot size as well in an amplifying process, and reasonably distributing the pumping power between two stages to obtain high power narrow linewidth intermediate infrared output.

Description

technical field [0001] The invention relates to the technical field of solid-state lasers, in particular to a device and method for generating high-efficiency narrow-linewidth mid-infrared lasers. Background technique [0002] Optical Parametric Oscillation (OPO) and Optical Parametric Oscillation Amplification (OPA) are commonly used methods to generate high-power mid-infrared lasers. It is usually called signal light in OPO with shorter output wavelength, and idler light with longer wavelength. . [0003] Compared with birefringent phase matching technology, quasi-phase matching technology (QPM) has no limitation of wave vector direction and polarization direction. By properly selecting polarized beams, using the maximum nonlinear coefficient of crystals, and adopting non-critical phase matching methods, the gap between beams can be eliminated. Walk-off effect, and PPMg: OLN crystal has high effective nonlinear coefficient, high anti-damage threshold and wide tunable rang...

AI Technical Summary

Problems solved by technology

However, its output light width is relatively wide, and it changes with the input light wavelength. The output high-power parametric light width is generally several nanometers to tens of nanometers.

[0004] The current research focus is to add spectral compression devices such as volume Bragg gratings and F-P etalons to the OPO cavity to control the linewidth of the parametric light, and then pass it into the first-stage OPA for amplification, but the addition of these devices increases the optical path. The difficulty increases the parameter oscillation threshold, reduces the parameter conversion efficiency, and is expensive

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