METHOD FOR MANUFACTURING OPTICAL DEVICE, METHOD FOR MANUFACTURING LASER DEVICE, METHOD FOR ADJUSTING BEAM QUALITY OF LASER DEVICE

摘要

An optical device 30 has a GRIN lens 35, a preceding-stage optical fiber 31 from which a light beam is entered to the GRIN lens 35, and a subsequent-stage optical fiber 32 to which a light beam emitted from the GRIN lens 35 is entered. A method for adjusting beam quality includes a measurement process P2 in which a light beam is entered to the preceding-stage optical fiber 31 and the beam quality of a light beam to be emitted from the subsequent-stage optical fiber 32 through the GRIN lens 35 is measured, and an adjustment process P3 in which the length of the GRIN lens 35 is adjusted on the basis of a result in the measurement process P2.