Junichi Asada

TL;DR: In this paper, a scanning color laser microscope comprises red, green and blue laser sources, objective lenses for focusing R, G and B laser emitted from R, B and C laser sources on a specimen, respectively, condenser lenses for condensing R and G laser lights reflected from or transmitted through the specimen.

TL;DR: An optical head arranged in such a manner that light emitted from a semiconductor laser (8) is inputted and coupled in a waveguide layer (3C) by a grating coupler (4C) having a concentric or spiral structure formed by concavities and convexities, passing toward to outer periphery in the layer, the waveguide light (12C) is shifted at the outermost peripheral portion of the waveguera-layer to a wavegueta-layer (3B) so as to convert the wave-guide light(12C

TL;DR: In this paper, an optical disk device is provided that can realize favorable recording/reproduction of signals on/from a hologram having a plurality of signal planes arranged in proximity to each other.

TL;DR: In this paper, an optical disk device has an aperture of an objective lens in an incoming path of a beam from a semiconductor laser to an optical disks formed larger than an aperture in a return path from the optical disk or an aperture is varied in recording and in reproduction.

TL;DR: An optical head employing a concentric-circular grating coupler (CGC) and a concentrics-and-couplers (CFGC) system is proposed, and its operating principle and characteristics are reported.