OPTICAL DEVICE AND METHOD FOR MANUFACTURING OPTICAL DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an optical device configured to reduce a coupling loss while suppressing generation of reflected return light, and a method for manufacturing the optical device.SOLUTION: The optical device includes: a multicore fiber 10 having a plurality of first cores 11 having optical axes X1 parallel to one another, and a first clad 12 enclosing the first cores 11; a plurality of single core fibers 20 having second cores 21 and second clads 22; a first optical system S1 in which an interval between optical paths is adjusted by arranging optical paths from the first cores 11 to be not parallel to one another; a second optical system S2 in which optical paths are arranged in parallel to one another to condense light into the respective second cores 21; and an adjusting part to equalize optical path lengths from the second optical system S2 to end faces 20a of the second cores 21. The optical axes X2 of the second cores 21 are parallel to one another; an interval B2 between the second cores 21 is larger than an interval B1 between the first cores 11; and the end face 20a of each second core 21 is not orthogonal to the optical axis X2 of the second core 21.