Cascaded nonlinear optical frequency conversion device for realizing 1064nm to 400-450nm blue-violet light

Abstract

The invention discloses a cascaded nonlinear optical frequency conversion device for realizing 1064nm to 400-450nm blue-violet light, and belongs to the field of laser technologies and nonlinear optical technologies. A 1064nm laser resonant cavity is formed by a resonant cavity input mirror and a resonant cavity output mirror; a resonant cavity intermediate mirror is placed in the 1064nm laser resonant cavity, and a 1064nm laser medium and a Q switch are sequentially placed between the resonant cavity input mirror and the resonant cavity intermediate mirror; nonlinear crystals with different functions are sequentially placed between the resonant cavity intermediate mirror and the resonant cavity output mirror; the 1064nm laser pumping OPO crystal generates 1.5[mu]m waveband laser, and generation of 400-450nm waveband blue-violet laser is further realized through combined design of frequency multiplication and sum frequency of the 1064nm waveband laser and the 1.5[mu]m waveband laser inthe cavity. According to the invention, an intracavity nonlinear optical frequency conversion mode is adopted, and the conversion efficiency of nonlinear optical frequency conversion is improved; andas an OPO crystal, a 1064nm pumping non-critical phase matching structure is realized, and the generation of 1.5[mu]m waveband laser with maximum efficiency is ensured.

Description

technical field [0001] The invention relates to the fields of laser technology and nonlinear optics technology, in particular to a cascaded nonlinear optical frequency conversion device for realizing blue-violet light from 1064nm to 400-450nm. Background technique [0002] Solid-state blue-violet lasers with an output wavelength of 400-450nm can be used in many fields such as biomedicine, laser processing, laser display, and Raman spectroscopy. In the field of laser processing, there is an increasing demand for cutting highly reflective materials such as gold, silver, copper, aluminum and other metals and their alloys. The application scenarios of micromachining have received extensive attention. In the field of biomedicine, drug-resistant bacterial diseases caused by bacterial infections continue to occur. The threat of drug-resistant bacteria to global public health cannot be underestimated. New treatments need to be developed for highly drug-resistant infectious diseases...

AI Technical Summary

Problems solved by technology

However, the 0.9μm laser corresponds to Nd 3+ ion 4 f 3 / 2 — 4 I 9 / 2 The transition, which is a quasi-three-level structure, has inherent problems such as serious reabsorption loss and small stimulated emission cross section. The key to this frequency doubling scheme is to take appropriate measures to suppress the 1.06μm oscillation with a large emission cross section

In addition Nd 3+ ion 4 f 3 / 2 — 4 I 9 / 2 The wavelength of the transition is above 900nm, and the direct frequency doubling scheme cannot achieve a shorter blue-violet wavelength output

Using Cr 3+ : LiSAF, Ti 3+ : Sapphire and other media have wide fluorescence spectrum characteristics at 800-1000nm, and the blue-violet light output of 400-450nm can be obtained through intracavity frequency doubling, but doped with Cr 3+ , Ti-doped 3+ The laser needs laser pumping in the visible light band, and the overall cost is relatively high

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