Optical wavelength convertical apparatus

摘要

An optical wavelength converting apparatus for converting the divergent lights by a compact apparatus into a parallel lights comprises a light source, a means for collecting the lights from the light source to introduce them into the optical waveguide of the wavelength converting element, a rotation symmetrical lens disposed on the end portion opposite to the end portion on the side irradiated with the collected lights, thereby to make it possible to convert the divergent lights like Cherenkov radiation lights into parallel lights by a compact apparatus.