End-pumped mid-infrared KTA parametric oscillator

Abstract

The invention belongs to the technical field of parametric oscillators and relates to an end-pumped mid-infrared KTA parametric oscillator. The end-pumped mid-infrared KTA parametric oscillator comprises a pumping source, a coupling lens set, an Nd:YVO4 laser and an intracavity optical parametric oscillator arranged in the Nd:YVO4 laser, wherein the pumping source adopts a semiconductor laser withoutput wavelength of 808 nm and outputs a laser crystal passing through a laser crystal Nd:YVO4 pumped at the rear end of the coupling lens set; the Nd:YVO4 laser is a flat-concave cavity for generating linearly polarized 1064 nm laser light, and a laser crystal Nd:YVO4, an acousto-optic Q-switch and the intracavity optical parametric oscillator are arranged in the Nd:YVO4 laser in sequence; an anti-reflection film with 808 nm and an anti-reflection film with 1064 nm are coated at both ends of the Nd:YVO4 laser crystal; a 1064 nm high anti-reflective film and a 1.5-1.6 mum highly reflective film are coated on an input mirror for the intracavity optical parametric oscillator, a KTA crystal is arranged in the cavity mirror, and dielectric films for performing anti reflection to base frequency light 1064 nm, signal light 1.5-1.6 mum and idle light 3.5 mum are coated at the both ends of the cavity mirror. The mid-infrared laser output with low threshold value, high efficiency and high-repetition frequency can be obtained in the invention.

Description

technical field [0001] The invention relates to a high-efficiency and high-repetition-frequency Nd:YVO pumped by a diode end surface 4 A mid-infrared KTA parametric oscillator pumped by a laser belongs to the technical field of parametric oscillators. technical background [0002] 3-5μm is the most ideal atmospheric window, which has a wide range of applications in environmental monitoring, remote sensing, medical diagnosis and treatment, laser spectroscopy research, material processing, data communication, photoelectric measurement, laser ranging, laser radar, infrared countermeasures, etc. value and prospects. Using an optical parametric oscillator pumped by an all-solid-state laser to down-convert the frequency of the 1-2 μm near-infrared laser to the 3-5 μm mid-infrared laser is the most effective way to obtain an all-solid-state, tunable, high-power, narrow-linewidth laser output in this band. , and is by far the most mature and widely used method. [0003] Nonlinear...

AI Technical Summary

Problems solved by technology

For the mid-infrared KTA parametric oscillator with a repetition rate above several thousand Hz, foreign countries have used the intracavity parametric oscillator (IOPO) scheme to achieve a 3.5μm laser output exceeding 4W, but due to the semiconductor side pumping method, from the diode The light-to-light conversion efficiency of the output 808nm laser to the mid-infrared laser is less than 1%, and the repetition rate is only limited to 10kHz; there are also end-pumped IOPOs, and the light-to-light conversion efficiency is close to 4%. The saturable absorber is passively Q-switched, and its repetition frequency changes with the pump power, so it is not suitable for applications that require repetition frequency

The scheme adopted in the technical solution of the present invention using diode end-pumped acousto-optic Q-switch active Q-switched laser as the pumping source has not been reported in the relevant patents and documents of the mid-infrared KTA parametric oscillator

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