Abstract: An apparatus used to calibrate microtiter plate readers. The apparatus includes one or more structures having two exterior surfaces wherein one of the exterior surfaces is coated with a coating selected to establish on that surface a reflection loss that mimics reflection loss at an air-liquid interface, and the other of the two exterior surfaces is coated with a coating selected to establish a reflection loss on that surface that mimics the reflection loss at a bottom surface of a microtiter plate. The apparatus may be a single layer, a multi-layered composition or a container. The apparatus is an artifact that may be used to calibrate a plate reader by mimicking a solution-filled microtiter plate. The artifact may be used for a plurality of liquids, including water. The artifact produces reflection losses more closely mirroring reflection losses expected for a liquid-filled microtiter plate well.

Abstract: A laser energy sensor and methodology for measuring laser energy in a laser beam by photoacoustic means. Laser energy is converted into acoustic energy which is then measured and converted to an energy reading corresponding to the energy of a laser beam.

Abstract: A turbidity sensor for sensing the turbidity of a fluid in a working chamber in a household appliance is disclosed to include a light-transmissive body shell defining therein an accommodation chamber and covered with a cover member, and a sensor module, which includes a circuit board mounted in the accommodation chamber inside the body shell, a holder block a set of light-transmitting devices and a set of light-receiving devices on the circuit board in a right angle relationship for emitting light onto the fluid and picking up reflected light from suspended particles/impurities in the fluid for determination of the turbidity of the fluid.

Abstract: A system for monitoring tightness of stator windings in an electric machine is provided. The system includes a light source for providing an optical power. The system also includes an optical separation sensor situated in a stator core and including an optical interface element for absorbing some of the optical power. Further, the system includes a power meter for measuring at least one intensity of the optical power after absorption by the optical interface element and a control subsystem for assessing the tightness of the stator windings.

Abstract: A system for analyzing smoke has a plurality of units, wherein each unit includes an optical emitter for alternately directing horizontally and vertically polarized light along a beam path, and into a smoke cloud, to generate scattered light. A horizontally polarized detector and a vertically polarized detector are positioned at different locations, but at a same distance and scattering angle relative to the beam path. Each unit has a different wavelength. A computer receives signals from the detectors of all units, in response to each emitter, for analysis of the smoke.

Abstract: A method and an arrangement of measuring acidity or other chemical or physical property of a gas. The invention comprises a membrane having optical indicator molecules bound to a microporous matrix arranged to be placed into contact with the gas to be measured, the optical indicator molecules changing their colour in response to the acidity or other chemical or physical property of the gas, a light source, and a detector. The light source is arranged to emit and direct light to the membrane, the light being transmitted through the membrane, whereby a part of the light is absorbed into the optical indicator molecules, and the rest of the light emitted is guided to the detector, where it is measured.

Abstract: The present invention relates to a method for identifying transparent objects, for example measurement cuvettes, with the aid of their absorption spectrum and therefore makes it possible to protect articles against forgery or imitation.

Abstract: An optical tomography system for viewing an object of interest includes a microcapillary tube viewing area for positioning the object of interest in an optical path including a detector. A motor is located to attach to and rotate a microcapillary tube. A device is arranged for transmitting broadband light having wavelengths between 550 nm and 620 nm into the microcapillary tube viewing area. A hyperchromatic lens is located to receive light transmitted through the microcapillary tube viewing area. A tube lens is located to focus light rays transmitted through the hyperchromatic lens, such that light rays from multiple object planes in the microcapillary tube viewing area simultaneously focus on the at least one detector.

Abstract: An optical projection tomography system is illuminated with a light source. An object-containing tube, a portion of which is located within the region illuminated by the light source, contains an object of interest that has a feature of interest. A detector is located to receive emerging radiation from the object of interest. A lens, including optical field extension elements, is located in the optical path between the object region and the detector, such that light rays from multiple object planes in the object-containing tube simultaneously focus on the detector. The object-containing tube moves relatively to the detector and the lens operate to provide multiple views of the object region for producing an image of the feature of interest at each view.

Abstract: A localized plasmon resonance sensor for detecting a change in optical constant uses a structure including metal. In a response spectrum with respect to light incident on the structure, there are at least two resonance peaks including at least one resonance peak shifted to a longer wavelength side and at least another peak shifted to a shorter wavelength side, by the change in optical constant.

Abstract: A stored light intensity measurement device capable of measuring an afterglow intensity from a light storing sign in a simple way, even if the light storing sign is provided on walls or risers of stairs in facilities or underground shopping mall. The stored light intensity measurement device comprising the light measuring unit configured o measure afterglow from a part of a light storing section on a light storing sign, and calculation means for calculating an afterglow intensity from the light storing sign based on the measured results.

Abstract: The invention features an optical medium for calibrating UV absorbance detectors, methods for making such an optical medium, and methods for calibrating UV absorbance detectors using such a medium. The optical calibration medium includes a gel-sol silica glass monolith with a rare-earth dopant therein. The rare-earth dopant exhibits at least one spectral feature in at least the far UV range. The constituents of the gel-sol silica glass monolith are selected so the rare-earth doped sol-gel glass monolith exhibits a transmittance in the far UV range so each distinct spectral feature of the rare-earth dopant in the far UV range is discernable. The transmittance in a particular embodiment is at least about 50% at about 250 nm. The rare earth materials selected for use as dopants are those exhibiting a wide range of spectral features, preferably over a range from about 190 nm to about 700 nm and more particularly exhibit at least one distinct spectral feature in the range from about 190 nm to about 300 nm.

Abstract: The invention features an optical medium for calibrating UV absorbance detectors, methods for making such an optical medium, and methods for calibrating UV absorbance detectors using such a medium. The optical calibration medium includes a gel-sol silica glass monolith with a rare-earth dopant therein. The rare-earth dopant exhibits at least one spectral feature in at least the far UV range. The constituents of the gel-sol silica glass monolith are selected so the rare-earth doped sol-gel glass monolith exhibits a transmittance in the far UV range so each distinct spectral feature of the rare-earth dopant in the far UV range is discernable.

Abstract: An atomic absorption photometer with a hollow cathode lamp and a deuterium lamp uses for each a power source which receives a variable current and switches it on and off so as to output a constant voltage.

Abstract: The invention relates to a photomechanical transducer which comprises a photochromic element made of a first material and attached on a carrier element made of a deformable second material. The first material of the photochromic element changes its molecular shape when it is irradiated with light and thereby introduces a strain into the carrier element which as a result is deformed.

Abstract: A device is provided for aligning a laser. For example, such a device could be used to align a laser as part of a particle measurement device in a semiconductor process tool. The device consists of a rigid member with alignment marks which define the intended point of impingement of a beam emitted from the laser. The laser is moved to allow the emitted laser beam to extend upon the alignment device and impinge upon the alignment marks. When the laser beam impinges upon alignment marks, preferably formed near the center of the alignment device, the laser is determined to be in proper alignment. The device is configured having a outer circumference equal to the terminating element which the device replaces during the alignment procedure. The device is then removed from the semiconductor process tool and the terminating element, either a beam stop or a photodiode detector, is re-inserted. A procedure utilizing relatively few steps for properly aligning the laser is thereby provided.

Abstract: The invention relates to an analysis device for the automatic grading of products, in particular of fruits or vegetables, comprising punctiform lighting means (4, 8, 12) capable of generating a polarised incident beam, means (19) for deflecting the polarised incident beam which are capable of forming a crosswise line of light, lateral reflection means (22, 23) capable of allowing the products to be lighted laterally, lower reflection means (28, 29) capable of allowing the lower face of the products to be lighted, and separation means (6, 10, 14) aligned on the optical axis of the polarised incident beam and suited to separating said incident beam and the backscattered depolarised light energy.

Abstract: An optochemical sensor for measuring concentrations of analytes is provided with a reactive matrix preferably made of polymeric material capable of swelling. Further provided are a mirror layer and a layer of a plurality of discrete islands that are electrically conductive, between which layers the reactive matrix is positioned, the diameter of the islands being smaller than the wavelength of the light employed for monitoring and evaluation.

Abstract: An optical system for the attenuation of laser light for measurement purposes which includes four logical subassemblies including a first attenuator subassembly for the attenuation of high power laser light, a second attenuator subassembly for lower power attenuation of the laser light, a third lens subassembly for collecting beam size data simultaneously at multiple locations in space, and a fourth logical subassembly including a beam measuring assembly for recording the beam size data received from the lens subassembly for analysis of the beam characteristics. The first attenuator subassembly is provided with a pair of reflecting, opposed facing, fixed wedges. The reflecting wedges are selectively tilted to eliminate interference effects between their inward facing reflecting surfaces. The second attenuator subassembly further includes a pair of opposed facing and movable wedges arranged in series with a fixed filter.

Abstract: An optical filter structure for selectively blocking radiation of predetermined wavelength is described which comprises a layer of material characterized by transition from a superconducting phase to insulating phase upon heating to a characteristic transition temperature, deposited on a slab of dielectric material in the form of a plurality of multipole elements in a planar array of predetermined spacing of optical dimensions between adjacent rows and columns of said array.

Abstract: A color-change dosimeter film made of a halogen-containing polymer in which is dispersed an acid-sensitive leuco dye, which dye a) is substantially free from groups that are sensitive to high-energy radiation and b) becomes colored in acid. This color-change dosimeter film (1) remains substantially colorless upon exposure to artificial illumination, including fluorescent light, for at least several months, (2) becomes colored upon exposure to high-energy radiation and accurately indicates small changes in dosage by the intensity of its color, and (3) remains substantially unchanged in its intensity of that color after being stored for several months, whether or not exposed to artificial illumination. An article of either quantitative or qualitative determination of the extent of high-energy radiation exposure is also provided, displaying a colored message of words, codes, symbols, or patterns on a substrate after exposure to the high-energy radiation.

Abstract: An optical reflection band filter structure for selectively blocking radiation within a preselected range of wavelengths is described which comprises a plurality of multipole elements of preselected configuration deposited with prescribed spacing in a periodic array on a substrate of dielectric material, each multipole configuration comprising a central element having shape corresponding to the overall shape of the multipole and a plurality of adjacent connected segments, all comprising a material characterized by transition from superconducting phase to insulating phase, upon being heated to a characteristic transition temperature, the central element having predetermined thickness and each transition segment disposed outwardly from the center element having higher transition temperature than the next inwardly disposed transition segment, and the central element.

Abstract: An optical reflection band filter structure for selectively blocking radiation within a preselected range of wavelengths is described which comprises a plurality of multipole elements of preselected configuration deposited with prescribed spacing in a periodic array on a substrate of dielectric material, each multipole configuration comprising a central element of metal and having shape corresponding to the overall shape of the multipole and a plurality of spaced metal segments, each space between adjacent segments being filled with a segment of material characterized by a transition from superconducting phase to insulating phase upon being heated to a characteristic transition temperature, each transition segment disposed outwardly from the center of the multipole element having lesser thickness than, or different composition from, the next inwardly disposed transition segment, the innermost transition segments having thickness substantially equal to that of the metal segments and central element.

Abstract: An optical filter structure for blocking radiation at or shorter than a preselected design wavelength is described which comprises a substantially transparent dielectric host material having dispersed therethrough a multiplicity of grains in preselected size and volume density within the dielectric, the grains comprising a material characterized by a transition between insulating and superconducting states at a characteristic transition temperature. The grains have diametric size substantially smaller then the longest wavelength of light to be absorbed, the filter absorbing resonantly via the dielectric anomaly and being tunable through selection of volume fraction of the grains within the dielectric.

Abstract: A low-power programmable alarm clock system is provided for use with microprocessor-based reflectance photometer systems for generating an alarm control signal at pre-programmed alarm activation times. The system utilizes an alarm clock circuit which includes means for storing a count value corresponding to the number of predefined time periods existing between a given instantaneous time and a pre-programmed alarm activation time, means for generating a signal corresponding to the passage of each of said predefined time periods and using the generator signal to increment the stored count value each time the predefined time period has elapsed, and means for generating an alarm activation signal when the stored count value has been incremented to a predefined activation value.

Abstract: A technique for the simultaneous measurement, in real time, of the changes in mode size, pulse length, and power of a wavetrain of laser pulses delivered by mode-locked or other pulsed laser systems contemplates directing respective portions of the beam along each of three beam paths. The beam portions along the first and second beam paths are subjected to respective, and different, degrees of focusing, and then passed through respective non-linear elements which generate radiation at the second harmonic. The first harmonic components are removed, and the second harmonic components are passed to respective first and second detectors which generate signals representative of the total second harmonic energy along each of the first and second beam paths. The beam portion along the third beam path is passed to a detector which generates a signal representative of the total energy in the beam pulse. The three signals are combined to give values proportional to peak power, pulse length, and mode size.

Abstract: A radiometer controller (11) of a radiation detector (10) is provided with a calibration method and apparatus comprised of mounting all temperature sensitive elements of the controller in thermostatically controlled ovens (26) during calibration and measurements, using a selected temperature that is above any which might be reached in the field. The instrument is calibrated in situ by adjusting heater power (EI) to the receptor cavity (12) in the radiometer detector to a predetermined full scale level as displayed by a meter (30). Then with the heater de-energized and the receptor cavity covered, the voltage output, (E.sub.o) is set to zero as displayed by the meter. Next the preset power is applied to the heater and the output of the radiant measurement channel is applied to the panel meter. With this preset heater power producing the proper heat, the gain of the measurement channel is adjusted to bring the meter dispaly to full scale.

Abstract: A power meter for non-destructively measuring the power of a high energy er beam. The power meter includes a cell disposed in the flow path of a gas containing a laser radiation-absorbing species. The absorption coefficient of the absorbing species is small enough to allow the beam to pass through the cell essentially unaltered. The concentration of the absorbing species is modulated to modulate its absorption of the laser beam power and produce acoustic waves in the gas which can be detected and measured to give an absolute measurement of the power in the high energy laser beam.

Abstract: Light absorbing ultra-thin films mounted under a fixed strain exhibit the behavior of an optomechanicalor photomechanical transducer. The transducer responds to light in a quick and reversible manner converting a time-variable light source into a time-variable mechanical stress easily monitored by a device such as a strain gage.

Abstract: A hollowed frusto-conical member has its base mounted adjacent the output of a laser. The apex portion extends outwardly from the laser output. The design of the member causes laser light to reflect many times as it travels from the base at a large aperture of the member down to the apex or focal point. The member may be made from light absorbing plastic material which absorbs most of the laser light and reflects only an infinitesimal portion.

Abstract: A flat sandwich composite plate of nested wedge-shaped sheets of highly transparent and gray neutral density filter glasses is enclosed in a frame. A bracket on the frame mounts it on the carriage of an optical instrument which measures the light scattering characteristics of a series of samples traversed on a carriage past a photometering station. A surface of the composite plate has a mat finish which scatters the light passing through it. The density and thickness of the filter glass are arranged to cover a predetermined range of light scatter corresponding to that caused by the range of samples which the optical instrument can accurately measure. An appended flat section of filter glass provides light scatter characteristics corresponding to an auxiliary sample characteristic. The transmittance of the appended section is adjusted by a movable leaf and notched adjusting segments. The mat surface is obtained by frosting a surface of the filter glass by blasting or grinding with 9 micron grit.

Abstract: An optochemical sensor for measuring concentrations of analytes is provided with a reactive matrix preferably made of polymeric material capable of swelling. Further provided are a mirror layer and a layer of a plurality of discrete islands that are electrically conductive, between which layers the reactive matrix is positioned, the diameter of the islands being smaller than the wavelength of the light employed for monitoring and evaluation.