Contactless Optical Packaging Concept for Laser to Fiber Coupling

Abstract

A novel method for the laser to fiber coupling is presented in which coarse alignment is achieved through micromachined v-grooves and mirrors in a fused silica substrate. Furthermore, fine repositioning is done in a noncontact manner by using a femtosecond laser to induce localized nanoscopic volume changes in specific locations within the bulk of the substrate, which, once combined with monolithic flexures within the substrate, produces a highly controlled motion. Using this principle, we overcome inherent manufacturing/assembly tolerances to achieve near theoretical coupling efficiency in a permanent manner. This proof of concept demonstrates a novel packaging principle where a sub-nm positioning resolution is achieved over tens of micrometers range of motion, efficiently overcoming intrinsic manufacturing tolerances.