Digitally tunable microfluidic optical fiber devices

This communication introduces a digital design for tunable microfluidic optical fiber devices. In these systems, multiple, independently controlled microfluidic plugs are pumped into or out of overlap with a fiber structure to modulate its transmission characteristics. The devices described here use eight plugs, eight electrowetting pumps and a corresponding set of molded planar recirculating microchannels to control the depth of the narrow-band loss feature associated with a long period fiber grating. Optical measurements illustrate the digital and relatively fast operation of this type of microfluidic fiber device.