周期性极化铌酸锂晶体中半非共线型宽带光学参变放大理论研究

基于周期性极化铌酸锂晶体(PPLN)的准相位匹配光参变放大过程,通过倾斜周期极化铌酸锂晶体中极化域(极化光栅)一定角度,实现了介于共线匹配方式和非共线匹配方式之间的一种半非共线型准相位匹配方式,并以该匹配方式下的各光矢量几何关系得出相位匹配曲线,找到在特定抽运光和信号光波长下能获得宽带增益放大的周期极化长度。并研究其极化倾斜角度与温度特性。模拟计算表明,在合适的角度与温度条件下,该方式可以532 nm抽运光抽运的信号光在800 nm和1064 nm处均获得宽带光参变放大。

Based on noncollinear optical parametric amplification in periodically poled lithium niobate (FPLN) which is realized by quasi-phase matching (QPM) technology, we consider the possibility of semi-noncollinear phase matching method between collinear and noncollinear geometry. With this configuration and geometry of all vectors in periodically poled lithium niobate, phase matching curves can be obtained. A sure grating period can always be found to satisfy the broad bandwidth optical parametric amplification (OPA) at fixed wavelengths of pump and signal from the phase matching curves. By tilting periodically poled lithium niobate-crystal's parallel grating a sure angle and keeping a sure temperature, numerical simulation with proper parameter shows broad bandwidth OPA at signal wavelengths of 800 nm and 1064 nm can be achieved.