FIBEROPTIC DEVICE WITH LONG FOCAL LENGTH GRADIENT-INDEX OR GRIN FIBER LENS

摘要

A fiberoptic device achieves a substantially longer focal length by placing a beam expander between the terminal end of an optical fiber and a gradient-index (GRIN) lens to simulate free space therebetween. In one embodiment, a fiberoptic device comprises an optical fiber having a fiber core and an end through which a light beam emits from the fiber core; a beam expander having a first end coupled to the end of the optical fiber and having a second end, the beam expander permitting the light beam emitting from the fiber core to pass from the first end to the second end and to expand from the first end to a larger size at the second end; and a gradient-index fiber lens coupled to the second end of the beam expander to receive the light beam from the beam expander and focus the light beam.