Microfluidic tuning of distributed feedback quantum cascade lasers

In this Letter, we report the tuning of the emission wavelength of a single mode distributed feedback quantum cascade laser by modifying the mode effective refractive index using fluids. A fabrication procedure to encapsulate the devices in polymers for microfluidic delivery is also presented. The integration of microfluidics with semiconductor laser ( optofluidics) is promising for new compact and portable lab-on-a-chip applications. (c) 2006 Optical Society of America.