基于铌酸锂的高阶可调谐布拉格波导光栅特性分析  

Characteristic Analysis of High-Order Tunable Bragg Waveguide Grating Based on Lithium Niobate

作　　者：王钊[1,2] 张爱玲[1,2] 田红苗 李青青[1,2] 

机构地区：[1]天津理工大学电气电子工程学院,天津300384 [2]光电器件与通信技术教育部工程研究中心,天津300384

出　　处：《激光与光电子学进展》2017年第6期61-67,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(61377075)

摘　　要：提出了一种可在铌酸锂上利用光刻及钛扩散方法实现高阶可调谐的布拉格波导光栅结构,并对其相关特性进行了分析。分析了占空比、光栅阶数、波导宽度差及外加电压对高阶布拉格波导光栅反射谱特性的影响。结果表明,折射率调制度、最大反射率与零值带宽均随占空比呈周期性变化,中心波长随占空比的增加向长波方向漂移。在各阶光栅均取最佳占空比时,折射率调制度最大;随着光栅长度的增大,最大反射率增大而零值带宽减小。随着波导宽度差的增大,最大反射率及零值带宽均增大,中心波长向长波方向漂移。当外加电压增加时,反射谱谱线形状几乎不变化,中心波长会向长波方向漂移,且呈线性增长趋势。A high-order tunable Bragg waveguide grating can be prepared on lithium niobate by using the methods of photolithography and titanium diffusion. Its related characteristics are analyzed. The effects of duty cycle, grating order, waveguide width difference and applied voltage on the reflective spectral properties of higher-order Bragg waveguide gratings are analyzed. The results show that the refractive index modulation depth, the maximum reflectivity and the zero bandwidth of gratings change periodically with the duty cycle, and the central wavelength shifts to the longer wavelength with the increase of duty cycle. When the best duty cycle is chosen for each order grating, the refractive index modulation depth is the largest, and the maximum reflectivity increases and the zero bandwidth decreases with the increase of grating length. With the increase of waveguide width difference, both of the maximum reflectivity and the zero bandwidth increase, and the central wavelength shifts to the longer wavelength. Moreover, with the increase of applied voltage, the reflective spectral shapes almost remain the same and the central wavelength shifts to the longer wavelength and presents a linear growth trend.

关 键 词：光栅 光通信 高阶可调谐布拉格波导光栅 光刻 钛扩散 铌酸锂 

分 类 号：TN256[电子电信—物理电子学]