WAVELENGTH CONVERSION LASER DEVICE AND IMAGE DISPLAY DEVICE USING THE SAME

摘要

A wavelength conversion laser device includes a laser light source which outputs a laser beam; two reflecting surfaces which reflect the laser beam; a wavelength conversion element which is arranged between the two reflecting surfaces and converts the laser beam into a wavelength converted beam; and a light collecting optical system which collects the laser beams and makes them enter between the reflecting surfaces. The optical path of the laser beam is changed so that the laser beam reciprocates a plurality of times between the reflecting surfaces while changing an angle of entry to the wavelength conversion element, and at least one of the two reflecting surfaces has a curvature so that the laser beams are collected between the reflecting surfaces. The light collecting optical system is arranged to have the beam waist positions of the laser beam, which reciprocates a plurality of times between the reflecting surfaces, scattered within the wavelength conversion element. Thus, breakage of the wavelength conversion element and unstableness of wavelength conversion are eliminated, and high power wavelength converted beam can be obtained.