Abstract: A beam spot size enlarger waveguide for enlarging the beam spot size is connected to a beam spot size reducer waveguide for shrinking the beam spot size, along with the direction of the propagation of light beam; or the beam spot size enlarger waveguide, a beam spot size maintainer waveguide for maintaining the beam spot size constantly, and the beam spot size reducer waveguide are connected in the direction of the propagation of light beam.

Abstract: Utilizing propagation of light along with a region of high refractive index, an enlargement and a reduction of an optical beam-spot are achieved by a plurality of layers of the cruds, in which relationships in magnitude of the refractive index are defined with respect to a segment-like core.

Abstract: There is disclosed a harmonic modulation device of waveguide type including a semiconductor laser, a waveguide for generating a nonlinear optical harmonic of the semiconductor laser by keeping phase matching, means for leading an optical beam of the semiconductor laser to the waveguide, electrodes disposed on the waveguide, and means for modulating a refractive index of the waveguide electro-optically to modulate a phase matching condition and thereby modulate an intensity of the harmonic.

Abstract: A second harmonic generator having a wide acceptance of bandwidth of temperature and/or a high conversion efficiency and a method of fabrication thereof are disclosed. An equidistant arrangement of pole-inverted grating having a rectangular sectional profile and the direction of spontaneous polarization opposite to that of a substrate within an optical waveguide has been known to produce a high conversion efficiency of the second harmonic generator A second harmonic generator having such a structure, which has so far been impossible to fabricate, is formed utilizing the liquid-phase epitaxial method and the ion-implanting method. Further, the substrate and the optical waveguide are formed of the same type of material.

Abstract: Using an optical pickup, recording/reproducing of information is performed by irradiating light beams to an optical recording medium to form light spots. The optical pickup includes means for generating plural light beams, an optical waveguide for guiding the plural light beams in a row into a flat space, and a light deflecting element for deflecting the light beams, which run in the optical waveguide, within a plane formed by a vector perpendicular to a plane of the optical waveguide and a directional vector of the light beams. The light deflecting element deflects the plural light spots, which are to be arranged in a row, in a direction perpendicular to the light spot row to perform micro seek.

Abstract: An optical waveguide is comprised of an optical substrate and an optical thin-film optical waveguide layer and formed such that ##EQU1## where .theta. is an output angle, n.sub.o1 is an ordinary refractive index of the optical substrate for an ordinary beam, n.sub.e1 is an extraordinary refractive index of the optical substrate for an extraordinary beam, n.sub.o2 is an ordinary refractive index of the optical thin-film optical waveguide layer for the ordinary beam and n.sub.e2 is an extraordinary refractive index of the optical thin-film optical waveguide layer for the extraordinary beam, and an electrode for generating a surface acoustic wave for diffracting light is formed on the optical waveguide to construct a collinear optical deflector.

Abstract: The present invention relates to a surface acoustic wave element comprising a substrate, an optical waveguide layer formed on the aforesaid substrate to guide laser light from a laser light source, a surface acoustic wave portion for deflecting or modulating the laser light traveling through the aforesaid optical waveguide layer, a comb-shaped SAW electrode provided on the aforesaid optical waveguide layer to cause the aforesaid surface acoustic wave portion to generate surface acoustic wave, and a terminal provided on the aforesaid optical waveguide layer and connected to the aforesaid SAW electrode to apply a high-frequency alternating voltage thereto, wherein a protection cover is bonded by a viscoelastic adhesive having a refractive index smaller than that of the aforesaid optical waveguide layer to cover the aforesaid SAW electrode and surface acoustic wave portion with air space in such a manner that the aforesaid terminal is positioned outside thereof, and the manufacturing method of the surface acoust

Abstract: A sample is located so as to be close to a prism and a light beam coming from a light source is projected to the prism while varying the incident angle to the prism as a parameter. The incident light beam to the prism is propagated therein and light emerging from the bottom surface of the prism, which is in contact with the sample, is projected to the sample. At the same time the intensity of light reflected by the bottom surface of the prism is measured. Optical constants such as the refractive index, the film thickness, the distribution of the refractive index, etc. are obtained by calculation, starting from measured values thus obtained.

Abstract: An optical integrated circuit and an optical apparatus used in optical communication or an opto-electronics apparatus such as an optical disk recording apparatus, in which various kinds of aberration caused by wavelength variation of a light source when a semiconductor laser is used as the light source. An aberration correcting grating having such grating pitches as to nearly satisfy the Bragg condition preferably with respect to a certain wavelength of the semiconductor laser beam is used. As a result, lowering of incidence (entrance) and radiation (exit) coupling efficiencies of the grating coupler and aberration such as chromatic aberration can be prevented. Even if a multi-mode semiconductor laser is used as a light source, the characteristics of the optical integrated circuit and optical apparatus do not vary largely.

Abstract: This invention relates to a wave guide type optical device as an integrated optical device having formed thereon lens and grating having particularly high efficiency and a fabrication method thereof. The present invention is characterized in that a wave guide type optical device having high efficiency and high stability can be fabricated efficiently by forming a buffer layer made of a dielectric substance on a optical wave guide formed near the surface of a substrate having an acousto-optic effect, then forming a light wave control loading layer and finely working the loading layer and the buffer layer to a predetermined shape of a desired optical device.