UV laser fabrication and modification of fiber Bragg gratings by stitching sub-gratings with in situ fluorescence monitoring.

We present a method for synthesizing complex fiber Bragg gratings using femtosecond UV laser pulses and image projection from a small phase mask. Fiber gratings with arbitrary spectral reflectivity can be achieved by stitching short grating segments with proper phases. The relative phase between neighboring sub-gratings is controlled using in situ UV-excited fluorescence monitoring.

Phase-sensitive amplification using gain saturation in a nonlinear Sagnac interferometer.

Phase-sensitive amplification of picosecond optical pulses was demonstrated using an SOA as the nonlinear medium inside a Sagnac interferometer. Ratios of maximum to minimum gain of more than 3:1 were experimentally measured. Numerical simulations using a semiconductor amplifier model are consistent with experiments.

Dispensed polymer waveguides and laser-fabricated couplers for optical interconnects on printed circuit boards.

Optical interconnects can provide chip-to-chip data communication with much needed bandwidth as processor speed and density keep growing. Optical waveguides and couplers are essential components for implementing optical interconnections. Techniques for directly dispensing polymer waveguides in laser-ablated trenches on printed circuit boards and for fabricating optical couplers are presented for quick prototype of optical interconnects.