Patent ID: 6810047
Filing Date: 2004-10-26
Classification: H01S

Abstract:
A wavelength tunable external resonator capable of tuning a wavelength using an electrical signal, comprises:a light source for emitting beams of the plurality of wavelengths; a lens for making the beams from the light source in parallel; a diffraction grating for diffracting the parallel beams; a reflection mirror for reflecting incident beams; and an optical deflector positioned between said diffraction grating and said reflection mirror, for changing the direction of the diffracted beams from said diffraction grating by controlling the refractive index of the optical deflector depending on an application of the electrical signal, and then making beams of a specific wavelength propagate perpendicularly to said reflection mirror, wherein beams perpendicularly reflected by said reflection mirror are focused on said light source, and wherein said optical deflector comprises a slabwaveguide and a triangle shape portion of a p/n junction in a slab waveguide, wherein if a beam traveling through the slab waveguide passes through the triangle shape portion of the p/n junction, a refractive angle of the beam is controlled by variations in the refractive index, depending on variations in the density of a carrier in the slab wave guide by injection of current or application of voltage into/to the p/n junction.