Abstract: A wavelength conversion laser is provided with a pair of fundamental wave reflecting surfaces for reflecting a fundamental wave to define a plurality of fundamental wave paths passing a wavelength conversion element at different angles, and a control unit for controlling wavelength conversion efficiencies so that the wavelength conversion efficiency on a specific one of the plurality of fundamental wave paths extending in different directions between the pair of fundamental wave reflecting surfaces is highest.

Abstract: A large-area transparent electroconductive film having a high visible light transmittance, a suitable haze and a low sheet resistance and having an excellent in uniformity on a film surface and which does not require special crystal orientation. The large-area transparent electroconductive film according to the present invention is characterized in that the film is a fluorine-doped tin oxide film having a film thickness of 0.3 to 1 ?m, an average light transmittance is 70 to 90% in a wavelength range of 400 to 800 nm, a haze is 2 to 20% and a sheet resistance is 2 to 15 ?/?.

Abstract: A laser light source includes a fundamental laser generator that generates a fundamental laser light, a wavelength conversion element that is made of a ferroelectric crystal with a periodically poled structure and converts the fundamental laser light to a laser light having a different wavelength, a holding member that holds at least a part of an element surface of the wavelength conversion element that crosses a polarization direction of the periodically poled structure, and an insulation layer that is provided between the holding member and the element surface. Electric resistivity of the insulation layer is 1×108 ?·cm or higher.

Abstract: A wavelength converting laser includes: a fundamental-wave laser light source emitting a fundamental wave; and a wavelength conversion element converting the fundamental wave emitted from the fundamental-wave laser light source into a converted wave having a different wavelength from the fundamental wave, in which: a pair of fundamental-wave reflecting surfaces is arranged on both end sides of the wavelength conversion element in the directions of an optical axis thereof and reflects the fundamental wave to thereby pass the fundamental wave a plurality of times inside of the wavelength conversion element, and at least one of the fundamental-wave reflecting surfaces transmits the converted wave; and the pair of fundamental-wave reflecting surfaces allows the fundamental wave to cross inside of the wavelength conversion element and form a plurality of light-concentration points at places different from a cross point of the fundamental wave.