铌酸锂电光长周期波导光栅

Electro-Optic Long-Period Gratings on Lithium Niobate Waveguides

该文对用铌酸锂制作电光长周期波导光栅的研究进展进行了综述。讨论了用铌酸锂制作长周期光栅的难点,介绍了解决此难点所用的特殊铌酸锂波导的制作原理和方法,再重点论述了对铌酸锂电光长周期波导光栅的研究,包括包层模阶数、铌酸锂波导的结构参数对光栅性能的影响以及光栅的谐振波长的温度灵敏度。研究表明铌酸锂长周期波导光栅的强度和谐振波长可分别由电压和温度调控,使该器件能进一步开发成为新型高速动态光滤波器或调制器。目前在最佳样品中实现25dB光栅强度调控所需的驱动电压不超过49V,其谐振波长的温度灵敏度为-1.0nm/℃。

This paper reviews the development of electro-optic （EO） long-period waveguide gratings （LPWG） on lithium niobate （LiNbO3）. We first discuss the main difficulty of fabricating LPWGs on LiNbO3 and explain the principle and the method of forming a special LiNbO3 waveguide structure to overcome this difficulty. We then highlight the main findings from the study of EO LPWGs on LiNbO3, including the effects of using different cladding modes and waveguide parameters on the grating performance and the temperature sensitivity of the resonance wavelength. EO LPWG on LiNbO3 allows the grating strength and the resonance wavelength to be controlled effectively by the driving voltage and the temperature, respectively, and has the potential to be further developed into new dynamic optical filters and intensity modulators for high-speed applications. Our best sample demonstrated so far shows a grating strength of 25 dB at a driving voltage of 49 V and a thermally tunable resonance wavelength with a sensitivity of-1.0 nm/℃.