WAVELENGTH CONVERSION METHOD, WAVELENGTH CONVERSION DEVICE USING IT, AND NON-DIFFRACTION LUMINOUS FLUX GENERATION DEVICE

摘要

PURPOSE: To provide a wavelength conversion device in which precise positioning for making basic wave incident on a wavelength conversion element is not required, making a parallel beam and conversion in limit of diffraction can be performed, and high efficiency conversion of wavelength can be performed. CONSTITUTION: This device is provided with LD as the basic wave light source and a QPM SHG element 10 as a wavelength conversion element of a non-light guide type. A polarization inversion region (domain) of this QPM SHG element 10 is a thin film type, and periodic polarization inversion structure 12 is constituted by laminating this thin film type domain. And this device is provide with an axicon lens 14 as a non-diffraction luminous flux generation means generating non-diffraction luminous flux being the basic wave made incident on the wavelength conversion element.