Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Kouhei Teramoto

Yasuharu Koyata

Shigenori Shibue

Masao Imaki

Yoshihito Hirano

Kiyohide Sakai

Shinsuke Shikama

Jiro Suzuki

Takao Endou

Teruo Miyamoto

Kimihide Nakatsu

Sadakazu Tomita

A wavelength converting laser device includes a laser diode producing laser light and including an optical resonator having a pair of facing reflectors, including a reflecting surface having a shape reducing loss in the optical resonator, with regard to a specific horizontal transverse mode of laser light as compared to the loss in the optical resonator for other horizontal transverse modes, and a wavelength converter for converting the laser light into harmonic light.

Wavelength converting laser device

Provided are a speckle removing light source capable of removing speckle by using laser light whose wavelength is temporally changed and a lighting apparatus for producing an image from which the speckle is removed. Included are a light source for outputting laser light, and a light frequency modulator for temporally changing a wavelength of the laser light. The light frequency modulator has a predetermined period set for changing the wavelength of the laser light. Also, provided is a lighting apparatus, including a spatial light modulator illuminated with the laser light outputted from the speckle removing light source to produce an image. The spatial light modulator has a period set for producing the image, which is longer than the period for changing the wavelength of the laser light by the light frequency modulator.

Speckle removing light source and lighting apparatus

A reflection elementdisposed in an optical waveguide elementreturns a part of light to a semiconductor laser diode elementso that the semiconductor laser diode elementoscillates in a coherent collapse mode, and a semiconductor light amplifieris optically coupled to the optical waveguide element, and amplifies an optical output from optical waveguide element, so as to provide a high-power fundamental-wave light source.

Fundamental-wave light source and wavelength converter

Provided is a lighting apparatus capable of uniformly and efficiently lighting a spatial light modulator. The lighting apparatus includes: a light source for outputting laser light; a multimode optical fiber in which the laser light outputted from the light source propagates through an internal core whose lateral cross section is a substantially polygonal outer diameter shape; and spatial light modulator for producing an image with illumination light from the multimode optical fiber. In the lighting apparatus, the laser light is outputted from the light source and is propagated to the multimode optical fiber in which an outer diameter shape of the lateral cross section of the core is a substantially polygonal shape, whereby the spatial light modulator can be uniformly and efficiently lighted.

Lighting apparatus

An allowable temperature range satisfying phase matching conditions of a wavelength conversion device is widened. A wavelength conversion light source includes a semiconductor laser diode device () applied with an antireflection film (), a lens () arranged opposite to the semiconductor laser diode device (), an optical fiber () having a Bragg grating () arranged in a core thereof, and a wavelength conversion device () formed of a nonlinear optical crystal on which light from the semiconductor laser diode device () is incident. In the wavelength conversion light source, the semiconductor laser diode device () oscillates in coherent collapse mode.

Optical wavelength conversion light source

Wavelength conversion laser and image display

A screen panel includes a rigid glass, a lenticular lens and a Fresnel lens laminated with each other, and the edges of the screen panel are sealed. An air evacuation path is formed between the lenses by wires inserted between the contact surfaces of the lenses, or by convexes or concaves previously formed on one of the contact surfaces. Because of the provision of the air evacuation path, the air between the lenses of the screen panel is sufficiently evacuated, and the lenses can closely attached to each other. Therefore, the flatness of the screen panel can be enhanced, and the degradation of the image quality can be prevented.

Growing community of inventors

Tokyo, Japan

Kouhei Teramoto