基于电光调制的DKDP晶体OPCPA增益带宽特性研究

Study on Gain Bandwidth Characteristics of DKDP-OPCPA Based on Electro-Optic Modulation

提出了一种基于电光效应的新型光参量放大方案,理论分析了磷酸二氘钾(DKDP)晶体增益带宽随氘化率的变化特性,研究了70%和95%氘化率的DKDP晶体在不同电场强度下的增益带宽变化特性。在885 nm中心波长处,对70%氘化率的DKDP晶体施加大小为1.67×10^ 5 V/m的场强时,增益带宽可从90 nm拓宽至124 nm;在808 nm中心波长处,对95%氘化率的DKDP晶体施加大小为1×10^ 5 V/m的场强时,增益带宽可从52 nm拓宽至68 nm。结果表明,在光学参量放大系统中,通过线性电光效应可以有效拓宽系统的增益带宽,同时可通过电光调制调节增益谱的中心波长,以进行连续波长调谐,在高能超短激光系统中具有很大的应用前景。

In this paper, a new optical parametric amplification scheme based on electro-optic effect is proposed. The change characteristics of gain bandwidth of potassium deuterium phosphate (DKDP) crystal are theoretically analyzed with the change of deuteration rate, and the variation characteristics of gain bandwidth of DKDP crystal with 70% and 95% deuteration rate under different electric field intensities are studied. At 885 nm central wavelength, the gain bandwidth of DKDP crystal with 70% deuteration rate can be broadened from 90 nm to 124 nm when the electric field strength of 1.67×10 ^5 V/m is applied. At 808 nm central wavelength, the gain bandwidth of DKDP crystal with 95% deuteration rate can be broadened from 52 nm to 68 nm when the applied electric field is 1×10^ 5 V/m. The results show that the linear electro-optic effect can effectively broaden the gain bandwidth of the optical parametric amplification system, and the central wavelength of the gain spectrum can be adjusted by electro-optic modulation to achieve continuous wavelength tuning. It has a great application prospect in high-energy ultrashort laser system.