Patent ID: 7963677

Claim:
A light source device, comprising: a light source unit emitting light of a first wavelength; a wavelength converting element converting the light of the first wavelength into light of a second wavelength different from the first wavelength; an external resonator transmitting the light of the second wavelength emitted from the wavelength converting element to travel to a emission destination and reflecting the light of the first wavelength to resonate between the light source unit and the external resonator; a wavelength separating section transmitting the light converted from the first wavelength to the second wavelength in the course of traveling from the external resonator to the light source unit and reflecting the light of the first wavelength to separate the light of the first wavelength and the light of the second wavelength from each other; and a turnback section turning back the light of the second wavelength separated by the wavelength separating section toward the emission destination, wherein the wavelength separating section reflects the light of the first wavelength from the light source unit to travel toward the wavelength converting element.