Abstract: A surface optical device apparatus includes a surface optical device capable of emitting or receiving light through a surface thereof and a thick layer formed of a radiation-curable or electron-beam-curable material, such as a polymerizable resist. In the thick layer, a guide hole for inserting an end portion of a light-transmission member, such as an optical fiber, and a plastic optical fiber with a flat end face or a lens-shaped end face, therein is formed at a position corresponding to the surface of the surface optical device such that the surface optical device can be optically coupled to the light-transmission member inserted in the guide hole. The guide hole is formed in the thick layer by performing a patterning on the thick layer using photolithography to selectively harden the thick layer and developing the thick layer.

Abstract: An optical wavelength converting apparatus comprising first and second light sources and a nonlinear optical material. Beams from the two light sources, incident on the material, generate sum frequency light of these beams. The nonlinear optical material is provided with a periodic structure that matches phases of the beams from the two light sources with a phase of the sum frequency light of these beams. Also, wavelengths of the beams from the two light sources and of the sum frequency light of these beams, polarization directions of these three beams in the material, and propagation directions of these three beams in the material are determined such that an efficiency of conversion into sum frequency light does not change even with a change in one of the defining parameters, thus providing an advantageous pumping light source.

Abstract: An optical waveguide includes a partial cylindrical portion, and a plurality of end portions. The partial cylindrical portion has an elongated profile, and is formed of a material transparent to light propagating along the partial cylindrical portion. The end portion has an approximately partial spherical profile, smoothly joins the partial cylindrical portion, and is formed of the same material as the material of the partial cylindrical portion, so that the light propagates along the partial cylindrical portion and the end portions while repeating total reflections at a boundary surface contouring the partial cylindrical portion and the end portions.

Abstract: An optical wavelength converting apparatus includes a first semiconductor laser, a second semiconductor laser, and a wavelength converting element for converting first and second laser light from the first and second semiconductor lasers to sum frequency light. In this apparatus, the first semiconductor laser and the wavelength converting element are arranged so as to establish an external resonator structure in which the first laser light can be put under a resonant condition, and an optical path of the second laser light is so determined that the second laser light can propagate through the wavelength converting element.

Abstract: There is provided a harmonic generator generates high power laser light and can be modulated at high modulation rate. The semiconductor laser emits a first output light when a bias current is supplied, and a second output light when a modulating current is superposed to the bias current. On of the first output lights has a wavelength inside of a wavelength tolerance of phase-matching of the wavelength-converting element. The other has a wavelength outside of the wavelength tolerance of phase-matching.

Abstract: A surface emitting semiconductor laser includes an active region formed on a growth substrate, upper and lower mirror layers that sandwich the active region to construct a vertical cavity, a selective oxidization layer, and a current injecting unit for injecting a current into the active region. The selective oxidization layer is selectively oxidized and insulated and is provided on the side of the active region opposite to the side of the substrate. In this structure, a post portion is formed by removing semiconductor material formed on the substrate down to an uppermost or halfway level of the selective oxidization layer while the selective oxidization layer is used as an etch stop layer, and the selective oxidization layer acts as both a current confinement layer for the current injection and an insulating layer for the current injecting unit.

Abstract: There is provided an optical wavelength converting apparatus comprising a first and second light sources and a nonlinear optical material so that beams from the two light sources are allowed to be incident on the nonlinear optical material to generate sum frequency light of these beams, wherein the nonlinear optical material is provided with a periodic structure that matches phases of the beams from the two light sources with a phase of the sum frequency light of these beams, and wavelengths of the beams from the two light sources and of the sum frequency light of these beams, polarization directions of these three beams in the nonlinear optical material, and propagation directions of these three beams in the nonlinear optical material are determined such that an efficiency of conversion into sum frequency light does not change even with a change in at least one of parameters defining the efficiency of conversion into sum frequency light, whereby an inexpensive LD having poor wavelength stability can be used

Abstract: Light beams having different wavelengths emitted from red and blue semiconductor lasers and a laser diode pumped green solid-state laser are incident on respectively different surfaces of a color combining element and are overlaid on a single light path. Multiple beam interference films of the color combining element allow only the light beams having the oscillating wavelengths corresponding to the respective light sources to pass therethrough or reflect thereon so as to combine the light beams. A collimator collimates the light beams so that the beam waist of the light beams lies around a projection plane. When two-dimensional scanning is performed by radiating the light beams onto a micromechanical mirror and then onto a galvanometer mirror for scanning light in the horizontal and vertical directions, respectively, a color image is displayed on the projection plane by arranging pixels in array, each pixel consisting of overlapping pulses of light of three colors.

Abstract: In an image display apparatus having a light source having a plurality of light emitting devices, and making lights from the light source scan in a main scanning direction and in a subscanning direction to display on a screen an image having a predetermined number of pixels, scanning lines in the main scanning direction formed by the lights emitted from each of the light emitting devices are controlled to be superposed one on another on the screen. The plurality of light emitting devices in the light source may be separated into a certain number of light emitting device groups respectively outputting lights with which different image areas on the screen are irradiated. The light emitting device groups may be arranged in a direction corresponding to subscanning or in a direction corresponding to main scanning while being spaced apart from each other by a distance determined on the basis of a pixel pitch in the main scanning direction or the subscanning direction.

Abstract: A surface plasmon resonance sensor apparatus includes a common substrate, a surface emitting laser, such as a VCSEL, arranged on the common substrate, a sensor array, such as CCD array, arranged on the common substrate, a light-transmitting medium provided above the common substrate, and a metal thin film formed on the light-transmitting medium to cause surface plasmon resonance due to light which is emitted from the surface emitting laser, transmitted through the light-transmitting medium and impinging on the metal thin film. The surface emitting laser, metal thin film and sensor array are positioned such that a change in an intensity of light reflected by the metal thin film caused by the surface plasmon resonance can be measured by the sensor array.

Abstract: A surface optical device apparatus includes a surface optical device capable of emitting or receiving light through a surface thereof and a thick layer formed of a radiation-curable or electron-beam-curable material, such as a polymerizable resist. In the thick layer, a guide hole for inserting an end portion of a light-transmission member, such as an optical fiber, and a plastic optical fiber with a flat end face or a lens-shaped end face, therein is formed at a position corresponding to the surface of the surface optical device such that the surface optical device can be optically coupled to the light-transmission member inserted in the guide hole. The guide hole is formed in the thick layer by performing a patterning on the thick layer using photolithography to selectively harden the thick layer and developing the thick layer.

Abstract: A surface plasmon resonance sensor apparatus includes a common substrate, a surface emitting laser, such as a VCSEL, arranged on the common substrate, a sensor array, such as CCD array, arranged on the common substrate, a light-transmitting medium provided above the common substrate, and a metal thin film formed on the light-transmitting medium to cause surface plasmon resonance due to light which is emitted from the surface emitting laser, transmitted through the light-transmitting medium and impinging on the metal thin film. The surface emitting laser, metal thin film and sensor array are positioned such that a change in an intensity of light reflected by the metal thin film caused by the surface plasmon resonance can be measured by the sensor array.

Abstract: A surface emitting semiconductor laser includes an active region formed on a growth substrate, upper and lower mirror layers that sandwich the active region to construct a vertical cavity, a selective oxidization layer, and a current injecting unit for injecting a current into the active region. The selective oxidization layer is selectively oxidized and insulated and is provided on the side of the active region opposite to the side of the substrate. In this structure, a post portion is formed by removing semiconductor material formed on the substrate down to an uppermost or halfway level of the selective oxidization layer while the selective oxidization layer is used as an etch stop layer, and the selective oxidization layer acts as both a current confinement layer for the current injection and an insulating layer for the current injecting unit.

Abstract: A light deflection device comprises a segmental sphere body having a deflection face portion for deflecting and transmitting an incident light beam, and a segmental sphere face portion opposing to the deflecting face portion, a base plate for supporting the segmental sphere body in a turnable manner, and a driving means for turning the segmental sphere body, the refractive index of the segmental sphere body being different from the refractive index of a space or medium brought into contact with the deflection face portion. A light deflection device array coomprises the light deflection devices arranged in a one-dimensional or two-dimensional array.

Abstract: A light deflection device includes a deflection member having a sphere body enclosing a deflection face portion for deflecting a light beam, or a segmental sphere body having the deflection face portion and a segmental sphere face opposing to the deflection face portion. The device also includes a supporting member for supporting the deflection member in a turnable manner, and a driver for turning the deflection member. The driver is provided on the sphere face of the deflection member, and at a position opposing the sphere face or the segmental sphere face of the deflection member to apply a driving force to the sphere face or the segmental face. In one embodiment, a light deflection device array includes the arrangement of light deflection devices in a one-dimensional or two-dimensional array.

Abstract: An integrated optical node includes a main waveguide, a sub-waveguide, a fixed-wavelength type optical coupler and a tunable type optical coupler. On the sub-waveguide, an optical receiver may be formed to detect light guided from the main waveguide to the sub-waveguide by the optical coupler and/or a laser may be formed to emit light to be guided from the sub-waveguide to the main waveguide by the optical coupler. The elements of the optical node are arranged on a common semiconductor substrate so that the optical node can be reduced in size.

Abstract: An optical semiconductor apparatus includes at least two semiconductor laser portions each having a light waveguide with an active layer and a distributed reflector, and a stimulating unit for independently stimulating the active layers of the light waveguides. The semiconductor laser portions are serially arranged in a light propagation direction. The light waveguides are constructed such that a difference between propagation constants for two different polarization modes in one of the waveguides is different from a difference between propagation constants for the two different polarization modes in the other of the waveguides.

Abstract: An improved compound semiconductor device, such as a distributed Bragg reflection type or distributed feedback type laser device, having regions with and regions without a diffraction grating. The device is fabricated without exhibiting surface irregularities by growing a first epitaxial layer on a semiconductor substrate, forming a fine uneven structure on the surface of the first epitaxial layer and growing a second epitaxial layer on the fine uneven structure. The fine uneven structure has a surface shape which exposes crystal orientations that facilitate subsequent epitaxial growth. In one embodiment, portions of the fine uneven structure are formed as a diffraction grating while other portions are formed insufficiently uneven to have a diffraction effect for any usable light wavelength. The fine uneven structure may suitably be shallow, have a short pitch or be provided at a slant to the light propagation direction, in order to preclude a diffraction effect.

Abstract: A semiconductor laser includes a semiconductor laser structure having an active layer. The laser structure is designed such that light in both of two polarization modes can be excited therein. First and second reflectors are provided, and at least one of them is a distributed reflector which determines first and second reflection wavelengths for the two polarization modes. A coupling unit is provided for coupling the laser structure and the first and second reflectors for either of the light of the two polarization modes at first and second coupling wavelengths, which respectively coincide with the first and second reflection wavelengths. One of the light of the two polarization modes at the first and second reflection wavelengths is selectively propagated along a cavity comprised of the laser structure and the first and second reflectors by a control unit. Thus, light oscillates in one of the two polarization modes at the first and second reflection wavelengths.

Abstract: A display device is constituted by disposing a first display layer and a second display layer between a pair of electrode plates including at least one transparent electrode plate. The first display layer contains a low-molecular weight mesomorphic compound dispersed in or impregnating a polymer matrix. The second display layer is formed by disposing a diffraction grating and being filled with the low-molecular weight mesomorphic compound. The display device is incorporated in a display apparatus to effect a good display with a high contrast ratio.