To provide a variable wavelength external resonator which can vary the wavelength by an electric signal, can successively very a wavelength at high speed, and uses a light deflector stably operating according to the electric signal.
A light beam emitted from a light source 301 is transformed to a parallel light beam by a lens 302a. The parallel light beam is diffracted on a diffraction grating 304, and is propagated through a light deflector 308 arranged between a reflecting mirror 305 and the diffraction grating 304. The light deflector 308 is configured so that an index of refraction can vary according to an input electric signal. Of light beams propagating through the light deflector 308, only a light beam with a specific wavelength is emitted perpendicularly to the reflecting mirror 305. Thus, the light beam with the specific wavelength is refocused on the light source 301.
LEE MYUNG LAE
KIM HYUN SOO
SONG JUNG HO
KIM KANG HO
