Effects of angular misalignments on fiber-optic alignment automation

Automation of fiber-to-optic alignment is critical to the development of cost effective fiber-optic component manufacturing technologies. Key to the alignment automation is the angular alignment automation, which is now unavailable. But angular misalignments are unavoidable in practical fiber-optic aligning process. This work evaluates the effects of pitch, yaw, and roll angular misalignments for a butt coupling scheme involving the optical coupling between a single-mode fiber and a laser diode. It is demonstrated that the coupling efficiency and misalignment tolerance are more sensitive to tilt, i.e., pitch and yaw angular misalignments than lateral ones. It is further demonstrated that the time for locating the optimal coupling position using conventional hillclimbing automation searching algorithm is a strong function of angular misalignments.