Patent ID: 7376161

Claim:
A modulation light source comprising: a DBR laser which outputs a fundamental light, and which includes a DBR part, a phase part and a gain part; a light wavelength conversion device characterized by a phase matching wavelength, wherein said wavelength conversion device is arranged to receive the fundamental light output by said DBR laser, and wherein said wavelength conversion device outputs a second harmonic light in response to receipt of light whose wavelength is substantially near the phase matching wavelength and outputs substantially no second harmonic light in response to receipt of light whose wavelength is deviated substantially from the phase matching wavelength; and a controller, wherein the controller provides a prescribed current to the gain part and the phase part, respectively and provides a current to the DBR part based on a PWM signal in which pulse width is modulated corresponding to an image signal, thereby modulating a wavelength of the fundamental light to deviate from the phase matching wavelength of said light wavelength conversion device.