Optofluidic devices fabricated by femtosecond lasers

The combination of microoptics and microfluidics, also known as optofluidics, is raising an increasing interest. Several research fields are benefiting from this approach, from reconfigurable optical devices to optical sensing in microfluidic devices. Recently, directly buried high quality waveguides and microfluidic channels have been fabricated by femtosecond lasers. The main advantages of this technique, compared with traditional ones, are: (i) it is a direct maskless fabrication technique; (ii) it has three-dimensional capabilities providing high flexibility in intersecting the optical and fluidic structures. In this work, a few optofluidic devices based on this technology will be discussed. On one hand, an ultrafast optical switch based on a polymer solution in a femtosecond-laser-fabricated microchannel is demonstrated. On the other hand, the integration of optical waveguides in a commercial lab-on-a-chip for capillary electrophoresis will be presented, thus allowing on-chip sensing of biomolecules and paving the way to compact, portable and fully automated bioassays.