Fabrication of optical splitter and passive alignment technique with a femtosecond laser

A novel packaging process using a femtosecond laser has been developed for passive alignment of planar lightwave circuit devices. With only one step of micromachining, optical splitter and U-grooves for fiber aligning are simultaneously defined on fused silica glass. The fiber aligned optical splitter has a low insertion loss, less than 4 dB, including an intrinsic splitting loss of 3 dB and excess loss due to the passive alignment of a single-mode fiber. Finally, the output field pattern is presented, demonstrating the splitting ratio of the optical splitter is approximately 1 : 1.