OPTICAL COUPLING DEVICE

摘要

PURPOSE:To enable the low-loss optical coupling between optical function elements integrated with plural devices by setting the normalized frequency at the connecting ends of optical waveguide layers at the value at which the low optical coupling loss is resulted. CONSTITUTION:A semiconductor substrate 101 of this optical coupling device has spot size converting waveguides 2 and the size or refractive index of the semiconductor layers to constitute the core parts of the optical waveguides 2 are formed to a tapered shape. The light wave spot size of a laser diode 104 is gradually converted by the optical waveguides 102 of this optical coupling device constituted in such a manner and is converted into a suitable size at the light exit end. The normalized frequency of the optical waveguides in the end face part connected to the other optical function element can be set at a suitable size and the low-loss optical coupling is attained according to the optical coupling device constituted in such a manner.