| Microchip electrophoresis offers many benefits over conventional chemical and biological separation techniques. In this work, deep-ultraviolet fluorine and near-infrared femtosecond fiber lasers were used to fabricate and integrate microchannels and waveguides in fused silica, borosilicate glass and polymethylmethacrylate. The laser processing parameters were optimized in terms of target fluence, focus depth, scan speed and projection mask geometry to produce low-loss near-surface waveguides and intercepting microfluidic channels. Single- and multi-mode waveguides were fabricated and compared on the basis of guided mode profiles as well as optical propagation and coupling losses. Several optofluidic structures for absorption and fluorescence photometry have been fabricated and characterized in terms of total insertion loss, stray-light-rejection, and optical collection efficiency. The electrophoretic separation of Alexa Fluor and Cy5 fluorescent dyes was demonstrated and dye concentrations down to 1.9 nM were detected. Chip topologies and packaging approaches are presented for applications in miniaturized high-throughput analyte separation and extraction. |
