Abstract:
The present invention provides a method for preventing cross-talk of incident light in a photosensor device. The photosensor device is formed on the substrate of a semiconductor wafer and comprises a plurality of MOS transistor sensors. The present invention first involves forming a dielectric layer on the semiconductor wafer, which covers each MOS transistor sensor. Thereafter, a plurality of shallow trenches are formed in the dielectric layer, followed by the formation of a barrier layer on the surface of the dielectric layer and on the inner surface of each shallow trench. Then, a metal layer is formed on the surface of the barrier layer and fills each shallow trench. Finally, a chemical mechanical polishing (CMP) process is performed to remove both the barrier layer and the metal layer from each shallow trench. The metal layer in each shallow trench is used to prevent cross-talk from occurring in each MOS transistor sensor in the photosensor device.
Abstract:
A fiber optic cable forms a temperature sensor arranged along an object or space to monitor the temperature thereof and detect overheating or fire conditions. An end of the sensor is con5 nected through an interface to a laser emitter and an optical receiver, which are further connected to a computer. The computer controls the laser emitter to emit a laser pulse into the sensor. The optical receiver receives the resulting reflection signal from the sensor, and provides a corresponding signal to the computer to be evaluated in connection with a nominal comparison signal. If any location of the sensor is subjected to an unacceptable temperature increase, the sensor's refractive characteristics are changed, to cause an additional reflection pulse in the reflection signal. By evaluating the amplitude and the return time of the additional reflection pulse, the temperature level and the location of the overheating condition are determined by the computer.
Abstract:
A strain sensor has a fiber Bragg grating fastened in a one-quarter circular arc to the strain sensing section of a strain sensor member. One end of the fiber Bragg grating is aligned in the longitudinal direction of the strain sensing section, while the other end is aligned at a right angle to the longitudinal direction. When longitudinal stress is applied, the fiber Bragg grating is elongated at one end and compressed at the other end, creating a high degree of chirp, thereby enabling strain to be measured with high sensitivity. The sensitivity is determined partly by Poisson's ratio, and thus is not limited by geometrical constraints on the strain sensing section.
Abstract:
A photosensor device, which is constituted of a light-applying fiber 107 to apply an inspection light to a subject to be inspected; a light-receiving fiber 108 to receive a reflected light from the subject to be inspected; a laser beam source 114 to emit the inspection light to the light-applying fiber; and a photosensor 113 to receive the reflected light via the light-receiving fiber; which are disposed in a casing 102. A disk inspection apparatus for inspecting surface conditions of a disk, which is constituted of a turning table 204 for rotating the disk; a photosensor body 205 disposed opposite to the surface of the disk; and a transfer means for reciprocally transferring the photosensor body in a direction perpendicular to a rotating direction of the disk along the surface of the disk; wherein the above photosensor device is utilized as the photosensor body.
Abstract:
An optical sensor is provided. The sensor includes an optical fiber having a free extremity on which a polymer layer is deposited normal to the longitudinal axis. A light source injects a analytical light beam in the fiber, which is reflected by the polymer layer. The reflected beam is analyzed by a spectrum analyzer, which determines the thickness of the polymer layer based on the Fabry-Perot effect. This thickness is related to a substance to be detected. An optical nose made from a plurality of such sensors is also provided, and may be used to detected a variety of substances.
Abstract:
A misalignment detection system for checking the coupling of a component and a medium via a receptacle of a connectorized arrangement. Power coupling measurements between an optical component and a fiber are presented as illustrative examples of the invention. A ferrule of a fiber is inserted into a bore of a receptacle that has the component attached to the end of the receptacle opposite of the bore. The ferrule of the fiber is attached to a support structure having an absorber spring between the structure and ferrule. A first force is applied pressing the ferrule into the bore. Also, a rotating force orthogonal to the first force is applied to the structure causing the ferrule to wiggle in the bore. Power measurements are taken while the first force is applied and then also while the rotating force is applied.
Abstract:
A delayed optical signal is generated from an inputted optical signal by cyclically transmitting the inputted optical signal between at least two ends of an optical medium and outputting the inputted optical signal from one of the ends of the optical medium after at least one transmission cycle via the optical medium. Each transmission of the inputted optical signal in a direction via the optical medium is carried out over a wavelength resource that is different from a wavelength resource used in a preceding transmission of the inputted optical signal in a direction via the optical medium. Interference among repeated transmissions of the inputted optical signal via the optical medium is therefore minimized or even avoided. Related apparatus and method are also described.
Abstract:
This system comprises at least one optical sensor (C1, C2, C3) comprising two Bragg gratings (B11, B12; B21, B22; B31, B32) written in two optical waveguides and having sensitivities adjusted so that the respective spectra of the two gratings have a relative spectral shift which depends on the parameter or parameters to be measured. The system also comprises an optical source (6) provided in order to supply light to the two optical waveguides so as to interrogate the latter, means enabling the light to pass successively through the two Bragg gratings of the same sensor, photodetectors in order to measure, on the one hand, the power level of light (R1) having passed only through one of the two optical waveguides and, on the other hand, the power level of light (Rnull1) having passed successively through the two optical waveguides, and means to process these power levels and supply the values of the parameter or parameters measured. The invention is applicable in particular to measurements of temperatures, stresses and pressures.
Abstract:
A spread illuminating apparatus includes at least one light source, a light conductive plate having the at least one light source disposed toward one end surface thereof, and at least one light controlling means disposed between the at least one light source and the light conductive plate. The at least one light controlling means is formed such that a plurality of transparent rectangular solids are stacked one over another vertically and horizontally, and that the transparent rectangular solids are put together by means of adhesive which can transmit light emitted from the at least one light source. The at least one light controlling means has a refractive index profile formed in both directions parallel to and vertical to the light exit surface of the light conductive plate thereby controlling light with respect to the both directions.
Abstract:
A detection system is used during irradiation of an interaction region of a structure with laser light. The structure includes embedded material. The detection system includes a focusing lens positioned to receive light emitted from the interaction region. The detection system further includes an optical fiber optically coupled to the focusing lens to receive light from the focusing lens. The detection system further includes a spectrometer optically coupled to the optical fiber to receive light from the optical fiber. The spectrometer is adapted for analysis of the light for indications of the embedded material within the interaction region.