Abstract: A phase shift measuring apparatus for detecting a phase shift of a light wave passing through an object to be measured, including:supplying device for supplying first and second light waves having different frequencies;optical device for directing the first light wave toward the object and combining the first light wave passing through the object and the second light wave to obtain a composite light wave;detecting device for receiving the composite light wave and detecting a measured beat signal; andmeasuring device for comprising the measured beat signal with a predetermined reference beat signal to measure a phase shift of the first light wave.A gradient index, a thickness distribution, and the like of an object can be obtained from the measured phase shift.

Abstract: An optical device is composed by sandwiching a deformable member between sandwiching members. The deformable member has a shear modulus decreasing toward the inside. The deformable member may be a combination of a core and a coating with different shear moduli or a single body having a continuoudly decreasing shear modulus. The sandwiching members may be a flat plate either transparent or opaque or a lens with or without reflecting film. Because of inner soft and outer hard elastic nature of the deformable member, the sandwiching members can easily change their relative position to change an optical path and an imaging position of the optical device with good durability.

Abstract: A variable focus optical element comprises plural elastic members superposed in the axial direction and a deforming member having an aperture to cause the elastic member to protrude therefrom or descend therein thereby deforming the surface of the elastic members, and the modulus of elasticity of an elastic member at the protruding side is selected larger than that of another elastic member adjacent to first-mentioned elastic member at the protruding side.

Abstract: A variable-focus optical device comprises an elastomeric member having a gradient of shear modulus along its optical axis, and a deforming member having an aperture adapted for causing projection or sinking of the elastomeric member therethrough or thereat to deform the surface of the elastomeric member. The gradient of shear modulus is preferably one of continuously decreasing from the surface toward the inside of the elastomeric member. The gradient of shear modulus is provided by a concentration gradient of an inorganic substance such as silica dispersed in an elastomeric substance such as polysilioxane.

Abstract: An optical coupler of good efficiency can be prepared at a low cost by making an optical waveguide and a grating of the optical coupler of a monomolecular layer or a monomolecular built-up film.

Abstract: This invention provides a device for measuring light incident on an optical system. This device includes an optical system defining an optical path, a beam splitter and a photo detector. The beam splitter has a relief type diffraction lattice having a plurality of semireflecting surfaces periodically arranged and included in a transparent body. The diffraction lattice is arranged to split a portion of the incident light by its effect of reflection/diffraction and its beam splitting efficiency having a predetermined distribution within the lattice area. The diffracted light from the diffraction lattice is directed to the photo detector.

Abstract: A device for measuring light incident on an optical system comprises an optical system defining an optical path, a plurality of diffraction lattices arranged in the optical path, each of the diffraction lattices comprising a plurality of periodically arranged semireflecting oblique surfaces, and photodetector means for detecting each of the diffracted lights from the diffraction lattices distinctively. The diffraction lattices are each of different predetermined areas; however, when even light is input, each lattice diffracts the same total quantity of light to its respective detector.

Abstract: An apparatus for dividing an original surface having image information into a plurality of areas and reading the image information with the use of a photosensor through a plurality of imaging systems provided correspondingly to said plurality of areas. The imaging systems for imaging the image information of the original surface on the photosensor include zone plates.

Abstract: An optical system for scanning a medium with a beam spot includes a light beam generator, a deflector for deflecting the light beam in a predetermined direction and in deflection plane, and an imaging optical system between the deflector and the medium for imaging the light beam from the deflector on the medium as a beam spot, the imaging optical system having at least one lens element mode of a moisture absorbing material. The lens element has a shape in which the dimension in a direction parallel to the deflection plane of the light beam is greater than the dimension in a direction perpendicular to the deflection plane of the light beam. A device mitigates any influence on the imaged condition of the light beam on the medium caused by the lens element being subjected to moisture.

Abstract: A system for measuring incident light includes: an optical system defining an optical path; a photodetector; and a plurality of beam splitters, with each beamsplitter having a different, predetermined area and adapted to be disposed in the optical path with, at any one time, only one beam splitter in the optical path; and means for measuring the light received by the photodetector.

Abstract: A device for splitting an incident light on an image forming optical system by a relief type diffraction grating. The device is constructed of a transparent substrate and a transparent filling layer having substantially the same refractive index as that of the transparent substrate, and the relief type diffraction grating is formed on the interface between the substrate and the filling layer. With such an arrangement, the reflectively diffracted light is detected by the photodetector without any undue influence in the image-formation based on the transmissively diffracted light.

Abstract: A camera having a holographic indicator in which a reconstructed image of hologram and an image of an object formed by an image forming optical system are formed on the same plane, so that the reconstructed image and the object's image can be observed at the same diopter through a common observation optical system.

Abstract: A camera having a holographic indicator in which a reconstructed image of hologram and an image of an object formed by an image forming optical system are formed on the same plane, so that the reconstructed image and the object's image can be observed at the same diopter through a common observation optical system.