Research On 1.57 Micron Optical Parametric Oscillation Laser Technology

Optical parametric oscillator(OPO),as an optical device which can be applied to laser frequency tuning,plays an important role in the field of laser ranging,photoelectric countermeasures,spectral detection and analysis.It is also an important part of the high resolution trace gas detection system based on differential absorption spectroscopy.The optical parametric oscillator can convert a single wavelength pumped laser into two coherent tunable beams by nonlinear optical interaction.The laser output properties of the optical parametric oscillator can be changed by selecting different nonlinear crystals,changing the crystal deflection Angle,and selecting different pump wavelength,so that the optical parametric oscillation technique has a wider laser output wavelength range,which makes up for the shortcomings of the existing laser band coverage.It greatly expands the advantage of qualitative and quantitative analysis of atmospheric trace gas detection based on Lidar technology.In this paper,the optical parametric oscillation process is theoretically analyzed.According to the threshold of the optical parametric oscillator and the phase matching conditions,the nonlinear coefficient,damage threshold and crystal deflection angle of the nonlinear crystal,optics optical parametric oscillation using potassium titanate phosphate(KTi OPO4,KTP)are calculated and analyzed.Based on theoretical analysis and simulation,the nonlinear oscillation process of optical parametric oscillators has been studied.A resonant cavity with high matching parameters with nonlinear crystals was independently developed.A temperature control module using semiconductor electric cooler(TEC)has been used to control the temperature of nonlinear crystals,achieving 1.57 μm optical parametric oscillator.Analyzed the error sources of laser energy,conducted laser energy parameter testing experiments,provided the calculation and analysis process of spatial parameters,and selected a more suitable second-order moment spot fitting algorithm.The Optical parametric oscillator design scheme can provide reliable theoretical analysis and experimental data support for design of the greenhouse gas lidar laser emission system.