周期极化铌酸锂晶体电控光栅

Electrically Controlled Grating Based on PPLN

提出周期极化铌酸锂晶体电控宽带光栅，并利用耦合波理论，推导出电控光栅的衍射光光强分布解析表达式。数值结果表明，该电控光栅的衍射光谱可被外加电场调控。在310V的外加电压下，1．21～1．83μm波段的1级光衍射效率达到60％以上，在1．5μm的1级衍射光衍射效率为70％；而在165V的外加电压下，0．68．0．92um波段的1级光衍射效率达到60％以上，在0．8μm的1级衍射效率为81％。该电控光栅响应时间短，故有望在高速光开关、波分复用器或调制器方面有重要应用。

An electrically controlled broadband grating based on periodically poled LiNbO3 is reported. According to the wave- coupling theory, the analytical expression of the diffraction intensity for the grating is derived, and the numerical results show that the diffraction spectrum of the grating can be tuned by an applied electric field. For example, with an applied voltage of 310 V, the diffraction efficiency of first order spectrum is greater than 60% over the band from 1.21 ~m to 1.83 ~m. Especially at the wavelength of 1.5 pm, it reaches 70%. With an applied voltage of 165 V, the diffraction efficiency of first order spectrum is more than 60% over the band from 0.68 txm to 0.92 ~tm. Particularly at the wavelength of 0.8 pro, it is up to 81%. Due to the short response time, the grating can be expected to have important applications in high-speed optical switches, wavelength division multiplexers or optical modulators.