Tunable microfluidic optical fiber

We describe a class of active, tunable optical fiber that incorporates multiple microfluidic plugs into interior fiber microchannels. The propagation characteristics of certain optical modes of these fiber waveguides can be usefully manipulated by controlling the positions and optical properties of these plugs, using actuators and pumps formed on the fiber surface. These hybrid microfluidic/silica structures offer versatile tuning capabilities in a format that preserves the advantages of conventional, passive optical fiber. As an example, we report an all-fiber, narrowband filter, whose transmission wavelength and attenuation are independently adjustable via microfluidic tuning.