Fabrication of single-mode circular optofluidic waveguides in fused silica using femtosecond laser microfabrication

We demonstrate fabrication of single-mode circular optofluidic waveguides in fused silica glass substrates using femtosecond (fs) laser assisted chemical etching based on slit beam shaping. The fabrication procedure consists of four steps: slit-assisted fs laser direct writing of fused silica, selective chemical etching, polydimethylsiloxane film bonding, and vacuum-assisted liquid filling. The combination of slit beam shaping and high numerical aperture objectives ensures very narrowly modified lines with nearly circular cross-sections during laser direct writing. Introduction of a string of extra-access ports allows production of uniform circular microchannels with the diameters of similar to 10 mu m and the lengths at the centimeter scale due to the improvement of wet chemical etching process. By vacuum-assisted filling a mixture of liquid paraffin and decane into a microchannel structure, a single-mode circular optofluidic waveguide embedded in glass can be obtained.

Automated summary

Single-mode circular optofluidic waveguides were fabricated on fused silica glass substrates using femtosecond laser-assisted chemical etching based on slit beam shaping. The fabrication process involved four steps, resulting in uniform circular microchannels with diameters around 10μm and lengths at the centimeter scale. Vacuum-assisted filling of liquid paraffin and decane mixture into the microchannel structure enabled the creation of a single-mode circular optofluidic waveguide embedded in glass.