A supercontinuum frequency conversion laser based on ppln crystal

Abstract

The invention discloses a PPLN crystal-based supercontinuum frequency conversion laser. The invention consists of a near-infrared supercontinuum pump source, a lens group, a PPLN crystal, a temperature control system, a precision adjustment frame and an off-axis parabolic reflector; the lens group is a collimating and focusing system composed of a first lens and a second lens ; The output end of the near-infrared supercontinuum pump source is located at the focus of the incident surface of the first lens; the PPLN crystal is placed in the temperature control system, and the incident end surface is located at the focus of the exit surface of the second lens; the focus of the off-axis parabolic mirror is located at the second lens At the focal point of the exit surface, the central small hole is collinear with the output end of the near-infrared supercontinuum pump source, the center of the first lens, the center of the second lens and the center of the PPLN crystal; the present invention utilizes the near-infrared supercontinuum pump source and the PPLN crystal Between frequency multiplication, sum frequency, difference frequency effect and self-phase modulation, stimulated Raman scattering effect, the output spectrum can cover visible light, near-infrared and mid-infrared bands at the same time, and the structure is compact and easy to adjust.

Description

technical field [0001] The invention relates to a supercontinuum frequency conversion laser system, in particular to a PPLN crystal-based supercontinuum frequency conversion laser. Background technique [0002] In recent years, supercontinuum has played an increasingly important role in the fields of environmental monitoring, meteorological detection, biomedicine, material processing, national defense and security due to its high beam quality of ordinary laser light sources and ultra-wide spectral characteristics of white light sources. At present, in terms of spectrum expansion, there have been reports of supercontinuum light sources in the ultraviolet, visible, near-infrared, short-wave infrared, and mid-infrared bands, and they are gradually commercialized. Usually visible light, near-infrared and short-wave infrared supercontinuum are generated in silica-based optical fibers, and mid-infrared supercontinuum are generated in soft glass optical fibers, such as fluoride opt...

AI Technical Summary

Problems solved by technology

However, due to the large absorption loss of the silica fiber in the infrared band, and the large loss of the soft glass fiber in the visible and near-infrared bands, it is difficult for the supercontinuum light source based on fiber pumping to simultaneously cover the visible, near-infrared and mid-infrared bands. Ultra-wideband supercontinuum output

In addition, due to the huge melting point difference between the silica fiber and the soft glass fiber, it is difficult to fuse and taper between the silica fiber and the soft glass fiber, so it is also difficult to realize the beam combining of visible light, near-infrared and mid-infrared bands by combining beams output

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