Abstract: An optical switch operating on thermooptic effects has a branching section heater for heating a branching section of a core and a branched core heater for heating a branched core. The heaters are controlled separately so that the branching section and the branched core can be heated to respective temperatures so as to minimize insertion loss of inputted light and to prevent outputting light from a port not intended for light output.

Abstract: The vertical charge transfer paths 205 have portions (regions A) whose both sides are defined, by the device isolation regions 202 and portions (regions B) whose one side is defined by the device isolation regions 202. The impurity concentration of the device isolation regions 202a used to define both sides is set lower than that of the device isolation regions 202b used to define only one side such that a narrow channel effect in the portions of the vertical charge transfer paths 205, whose both sides are defined, can be reduced.

Abstract: A gear-reduction device for measuring and transmitting the movements of a rotary object has a sequential arrangement of wheel/pinion pairs. Each wheel/pinion pair consists of a gear wheel and a pinion that are rigidly connected to a common gear axle. At least part of the gear wheels lie in different parallel planes that are inclined at an oblique angle in relation to the plane of rotation of the rotary object. The gear wheels are of equal diameter, and each of the pinions drives the next following gear wheel. The first wheel in the sequence of wheel/pinion pairs is driven by the rotary object, while the last of the pinions drives a swivel-mounted optical angle-measuring device.

Abstract: An X-ray CT apparatus comprises a large number of X-ray sources, a detector, and a collimator. The X-ray sources are arranged around an object P of inspection. The detector detects X rays emitted from the X-ray sources. The collimator is located between the X-ray sources and the object of inspection, and restricts the angle of emission of the X rays emitted from the X-ray sources so as to match the size of the detection surface of the detector.

Abstract: A wavelength division multiplexer/demultiplexer (WDM) for use in an optical network and in an optical performance monitor that minimizes increases in insertion losses over temperature variations has a structure for holding at least one optical component. A diffraction grating assembly having a substrate is held in relation to the at least one optical component by the structure. A lens assembly having a focal length is held in relation to the at least one optical component. The coefficient of thermal expansion of the lens assembly and structure are approximately equal. The grating assembly has an angular dispersion that changes with temperature and the product of the focal length and angular dispersion remains constant over temperature. The WDM further comprises a prism having a change in index of refraction with temperature that is approximately equal to a negative of a coefficient of thermal expansion of the substrate.

Abstract: This invention provides an angled-dual-axis confocal scanning microscope comprising a fiber-coupled, angled-dual-axis confocal scanning head and a vertical scanning unit. The angled-dual-axis confocal scanning head is configured such that an illumination beam and an observation beam intersect optimally at an angle &thgr; within an object and the scanning is achieved by pivoting the illumination and observation beams using a single scanning element, thereby producing an arc-line scan. The vertical scanning unit causes the angled-dual-axis confocal scanning head to move towards or away from the object.

Abstract: This invention provides an angled-dual-axis optical coherence scanning microscope comprising a fiber-coupled, high-speed angled-dual-axis confocal scanning head and a vertical scanning unit. The angled-dual-axis confocal scanning head is configured such that an illumination beam and an observation beam intersect optimally at an angle &thgr; within an object and the scanning is achieved by pivoting the illumination and observation beams jointly using a high-speed scanning element. The vertical scanning unit causes the angled-dual-axis confocal scanning head to move towards or away from the object, thereby yielding a vertical cross-section scan of the object, while keeping the optical path lengths of the illumination and observation beams unchanged. By incorporating MEMS scanning mirrors and fiber-optic components, the angled-dual-axis optical coherence scanning microscope of the present invention can be miniaturized to provide a particularly powerful tool for in vivo medical imaging applications.

Abstract: A plurality of slots, which incline in directions that focus toward a source of radiation, are formed in plates constructed of a radiation-absorbing substance. Similarly, a plurality of slots, which incline in directions that focus toward the radiation source, are formed in support members constructed of a radiation-absorbing substance. If the support members and the plates are combined by the engagement between the slots, a scatter-ray removing grid in the form of a lattice is constructed such that each support member and each plate incline toward the radiation source.

Abstract: The parallel radiation (12) emanating from a sample 4 in a known apparatus for X-ray analysis (for example, for diffraction) is analyzed according to wavelength and focused in a focus 20 by a parabolic multilayer mirror 14. A collimator 28 is positioned around said focus. The resolution of the apparatus can be enhanced by making the angular passage width of the collimator smaller than the maximum range of its reflection angle &agr;max. In accordance with the invention the resolution of the apparatus will be better defined and hence enhanced by implementing the exit collimator 28 in such a way that the angular value for the passage width from every reflecting point A or B of the mirror surface is substantially independent of the position of the reflecting points. Preferably, the exit collimator 28 is implemented in the form of two mutually parallel knife edges which are situated at different distances from the reflecting points of the multilayer mirror.

Abstract: A photosensor array is provided with one or more semiconductor layers having carrier generating regions for generating carriers by incident exciting light, and the positions of the carrier generating regions are set arbitrarily so as to equalize the balance of incident light in the direction of two-dimensional travel, so that sensing with less distortion can be achieved.

Abstract: A speckle readhead includes a light source that outputs light towards an optically rough surface. Light scattered from this surface contains speckles. The scattered light is imaged onto an image detector, captured and stored. Subsequently, a second image is captured and stored. The two images are repeatedly compared at different offsets in a displacement direction. The comparison having the highest value indicates the amount of displacement between the readhead and the surface that occurred between taking the two images. An optical system of the readhead includes a lens and an aperture. The aperture can be round, with a diameter chosen so that the average size of the speckles is approximately equal to, or larger than, the dimensions of the elements of the image detector. The dimension of the aperture in a direction perpendicular to the direction of displacement can be reduced. Thus, the imaged speckles in that direction will be greater than the dimension of the image detector elements in that direction.

Abstract: A beam rotation angle detecting apparatus includes a light receiving portion for detecting the incidence positions of at least two beams moving on concentric circles while describing a circle or an arc, and an arithmetic system for calculating and outputting the angle between a straight line linking at least two incidence positions detected by the light receiving portion together and a predetermined reference line.

Abstract: An optical encoder comprises a main scale (1) having scale gratings (11) formed thereon with a certain angular pitch along a measurement axis (x1) that describes a circular arc. It also comprises a detection bead (2) having photoreceptive optical gratings (7) formed thereon. The detection head is arranged relatively movable along the measurement axis (x1), opposing to the main scale (1). The photoreceptive optical gratings (7) on the detection head (2) have transparent and opaque portions alternately arranged with a certain distance pitch along a straight, grating arrangement axis (x2).

Abstract: A method of fabricating a fused-type directional coupler that can be made in a simple manner. The present invention is characterized in that a pair of optical fibers satisfying a particular phase match condition are previously selected to form a fused-type directional coupler. The two optical fibers are prepared by respectively tapering and etching two identical optical fibers. The present invention can be applied to fabrication of mode-selective directional couplers utilizing symmetrical high-degree modes such as LP02 mode as well as fabrication of mode-selective directional couplers utilizing asymmetrical high-degree modes such as LP11 mode.

Abstract: A method for positioning a movable reflector in an optical switch. A set of optical power values are generated by measuring optical power related to optical reflections from the movable reflection for a plurality of positions of the movable reflector. A processor is used to generate a mathematical approximation of a relationship of optical power versus reflector position based on the set of optical power values. A position of the movable reflector is chosen based on a point in the mathematical approximation of the relationship of optical power versus reflector position.

Abstract: A two-dimensional positioning apparatus for positioning an object in a two dimensional direction, wherein are provided a platen, a slider having two X-axis motors and sensors and a Y-axis motor and sensor disposed above the platen, a converter for providing signals to detect the X-axis position of the center point of the slider, a controller for feedback control of the slider in a X-axis direction and a yaw direction, and for feedback control in the Y-direction, and a converter circuit for converting output of the controller to propulsion commands to be supplied to the motors, wherein a limiter is provided to restrict one axis limits of the propulsion commands. In this manner, accuracy is improved and flexibility is increased.

Abstract: A phase difference plate (12) converts states of polarization of emergent light form a laser light source (13) and return light form an optical recording medium (5). A diffractive element (21) separates the return light from an optical axis leading from the laser light source (13) to the optical recording medium (5), and guides the return light to a photodetector (14) on the basis of a difference between the states of polarization of the emergent light and the return light. The polarization direction of emergent light from the laser light source (13) is arranged so as to be oriented in the radial direction of the optical recording medium (5) (in the direction of birefringence of the optical recording medium).

Abstract: An apparatus and method for enhancing an image of penetrating radiation scattered by objects concealed within a container. An image derived from penetrating radiation transmitted through the container is combined with a scatter image in regard to which it is accurately registered in such a manner as to provide enhanced visibility and photorealism of the combined image.

Abstract: A method and system for reconstructing an x-ray image from a partial orbit through the use of a “virtual” fan angle. The virtual fan angle is determined based upon the range of angular positions spanned by a source in a CT instrument or a selected smaller angle. Exposure data is obtained and he virtual fan angle is used to weight the exposure data. Image reconstruction can then proceed using the weighted exposure data. The described methods and system also function for data collected over a complete orbit.

Abstract: An optical waveguide circuit capable of controlling polarization crosstalk is provided. An under cladding is formed on a silicon substrate (11). A core is formed on the under cladding and has a waveguide structure in which one or more optical input waveguides (12) arranged side by side are connected at their exit ends with a first slab guide (13), which is connected at its exit end with an arrayed waveguide (14) composed of plural channel waveguides (14a) that are different in length with the difference preset, and the arrayed waveguide (14) is connected at its exit end with a second slab waveguide (15), which is connected at its exit end with a plurality of optical output waveguides (16). The top of the core is covered with an over cladding to form an optical waveguide portion (10) composed of the under and over claddings and the core.