减少聚合物阵列波导光栅损耗的蒸气回溶技术

阵列波导光栅(AWG)器件是波分复用(WDM)系统的一种关键器件,其中,聚合物阵列波导光栅由于其制备工艺、器件集成等方面的优势而受到人们的日益关注。侧壁散射损耗是聚合物阵列波导光栅损耗的一个主要因素,减少阵列波导光栅波导的侧壁损耗对制备低损耗阵列波导光栅具有重要意义。一种蒸气回溶技术被用来有效地减少硅基聚合物阵列波导光栅的散射损耗,该技术的机理是饱和溶剂分子融入并软化波导侧壁,增加其流动性,从而降低波导侧壁粗糙度。用扫描电镜方法验证了用该技术能获得更光滑的波导侧壁。对直波导和阵列波导光栅样品进行回溶处理,测试后得到直波导的侧壁散射损耗减少2.1 dB/cm,阵列波导光栅中心信道和周边信道的插入损耗分别减少5.5 dB和6.7 dB,串扰减少2.5 dB。

Steam-Redissolution Technique for Reduction of Polymer/Si Arrayed Waveguide Grating Loss

Arrayed waveguide grating(AWG is a key device in wavelength-division multiplexing(WDM system.Polymer arrayed waveguide grating has recently attracted much attention due to its easier fabrication and higher-denisity device integration.Sidewall roughness scattering is one of the main loss factors for polymer arrayed waveguide grating.Reduction of sidewall scattering loss plays an important role in fabricatiton of low-loss polymer arrayed waveguide grating.An efficient steam-redissolution technique is used to greatly reduce sidewall scattering loss in the polymer/Si arrayed waveguide grating.The mechanism of this technique is that saturated solvent molecules adsorb and get into sidewalls of waveguides and enhance their fluidity,and then reduce roughness of sidewalls.Smoother sidewalls are achieved and verified by a scanning electron microscopy.Both straight waveguides and arrayed waveguide grating devices are steam-redissolved and reduction of their sidewall scattering loss is further measured.The sidewall loss in straight polymer waveguide is decreased by 2.1 dB/cm,the insertion loss of an arrayed waveguide grating device is reduced by about 5.5 dB for the central channel and 6.7 dB for the edge channels,and the crosstalk is reduced by 2.5 dB after the steam-redissolution.