OPTICAL SYSTEM, AND OPTICAL COMMUNICATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an optical system capable of reducing the cost of parts without lowering a coupling efficiency when at least two sheets of lenses are arranged even in the case of causing temprtature variation or the like, and to provide in the optical system for coupling a light emitting part to a light incident part, and to provide an optical communication device including the optical system. SOLUTION: In the optical system, the light emitting part is coupled to the light incident part with at least two sheets of lenses 13, 15. Only a lens 13 having larger NA is formed of a material small in the change of refractive index against the environmental change. COPYRIGHT: (C)2006,JPO&NCIPI