Low-loss optofluidic waveguides in fused silica enabled by spatially shaped femtosecond laser assisted etching combined with carbon dioxide laser irradiation

作者：Yu, Jianping; Xu, Jian^*; Dong, Qiaonan; Qi, Jia; Chen, Jianfang^*; Zhang, Aodong; Song, Yunpeng; Chen, Wei; Cheng, Ya^*

来源：Optics and Laser Technology, 2023, 158: 108889.

DOI：10.1016/j.optlastec.2022.108889

• FABRICATION
• GLASS

We demonstrate the fabrication of low-loss optofluidic waveguides encapsulated in fused silica glass using femtosecond laser microfabrication followed by carbon dioxide laser irradiation. Spatially-shaped femtosecond laser-assisted chemical etching is first used to fabricate microchannels with circular cross-sections and a string of open extra-access ports in the glass. Further, the carbon dioxide laser direct writing on the glass surface is used to create a thermal reflow effect of etched glass microstructures for simultaneously polishing all internal surfaces of channels and sealing the extra-access ports. With this effect, the inner surface roughness of the etched microchannels can be reduced to -40 nm. Finally, a single-mode microfluidic optical waveguide with a propagation loss of -0.78 dB/cm at 1310 nm is obtained inside the glass by filling a mixture solution of decane and liquid paraffin into a laser-polished microchannel.

• 单位
  中国科学院; y; 中国科学院研究生院; 同济大学