面向光背板应用的低损耗单模聚合物光波导技术研究

Research on Low Loss Single-mode Polymer Waveguides for Optical Backplane Applications

系统地开展了基于光刻及湿法显影工艺制备的聚合物光波导散射损耗的理论及实验研究。研究了包括粗糙度、波导尺寸和工作波长等主要参数对散射损耗的影响,采用激光共聚焦显微镜测量了光波导侧壁及上下表面的粗糙度。实验结果表明,波导侧壁的平均粗糙度约为60 nm,是上下表面粗糙度的3倍。因此,散射损耗主要由侧壁粗糙引起,其大小是上下表面粗糙引入散射损耗的9倍。基于上述理论及实验结果,通过优化波导设计,制备了工作于1 310 nm波长、平均损耗为0.35 dB/cm的低损耗单模聚合物光波导,其作为高速高密度光背板的关键传输介质具有良好的应用前景。

The roughness-induced scattering loss(LossR) of photolithography-fabricated polymer optical waveguide was investigated theoretically and experimentally. The effects of the LossRincluding roughness, waveguide dimension, and operation wavelength on the LossRwere studied. The roughness of the waveguide’s sidewall and top/bottom surface was measured by employing a laser confocal microscope. The results show that the average roughness of sidewall is about 60 nm, which is 3 times of that of top/bottom surface. As a result, the LossRof sidewall is dominant and is 9 times of that of top/bottom surface. Based on the above theory and experimental results, low-loss single mode polymer waveguides operating at the wavelength of 1 310 nm with average loss of 0.35 dB/cm were designed and fabricated, which have broad application prospect as the key transmission media of the high-speed high-density optical backplane.