利用有机-无机溶胶-凝胶方法制备平面波导环形谐振腔

采用简单的有机-无机混合的溶胶-凝胶方法制备了折射率在一定范围内可调的波导材料,并利用其制备了平面波导环形谐振腔器件。波导结构呈现倒脊形,其制备工艺首先是利用感应耦合等离子体刻蚀技术(ICP)在二氧化硅衬底上刻蚀波导结构的凹槽,然后再沉积波导薄膜。利用光谱仪对器件的传输特性进行了测量,观测到具有10 dB对比度,自由光谱范围0.182 nm周期性谐振现象,结合环形谐振腔的传输特性,得到环形腔具有较低的传输损耗1.7 dB/cm。同时对环形谐振腔的温度特性进行了测量,得出波导材料的热光系数为-1.54×10-4/℃。

An Integrated Optical Waveguide Ring Resonator by Using Sol-Gel Technology

An organic-inorganic hybrid waveguide material was synthesized by using simple sol-gel method. An integrated ring resonator was fabricated as follows. Grooves with the designed waveguide pattern were etched into the SiO2 layer on the Si substrate by using inductively coupled plasma (ICP), and subsequently the sol-gel material was coated on the structured surface. The finished waveguide is an inverted ridge waveguide with a sol-gel material core and SiO2 surrounding. The spectral characteristics of the device were measured by an optical spectrum analyzer in a set-up with fiber coupling. A periodically vibrated resonance spectrum was observed with 10 dB contrast and 0.182 nm period. According to the experimental data and the theoretical formula of the ring resonator, transmission loss of 1.7 dB/cm in the ring resonator was obtained. Relation of the characteristics and the temperature was also studied to give a thermal-optic coefficient of -1.54×10-4 /℃, which is much higher than conventional silica waveguide material. With the high thermo-optic coefficient, this device can hopefully find applications in thermo-optic switches, sensors and so on.