The alignment of optical fibers is very critical in optoelectronic packaging. A slight offset in any direction may severely affect the performance of the photonic device. Recently, passive alignment of optical fibers has attracted substantial attention due to its lower manufacturing cost and faster processing time when compared with active alignment. For conventional passive alignment, the position of each optical fiber is defined by the geometry of a V-groove. The epoxy is dispensed from the top of the V-groove and another cover plate is usually required to press the fiber against the walls of the V-groove. In the present study, a new technique for epoxy dispensing is developed. Instead of being applied from the top of the V-groove, some low viscosity epoxy is dispensed in a “canal” first. The epoxy fills an adjacent “reservoir” and then flows into the V-groove. Subsequently the epoxy flow runs through the gap between the optical fiber and the V-groove walls. It is observed that the flow of epoxy can align the optical fiber by the surface tension. Once the optical fiber is aligned and the epoxy is cured, more epoxy is applied in a glob-top manner to mechanical enhancement. In this paper, the configuration of the V-groove and associated features, the epoxy dispensing process, and the results of alignment are presented in details.
Tapered optical fiber waveguide coupling to whispering gallery modes of liquid crystal microdroplet for thermal sensing application