Abstract:
A semiconductor light source with optical feedback includes a vertical member extending upward from an upper horizontal surface of a header parallel to a vertical beam projected from a semiconductor light-emitting element mounted on the horizontal surface of the header wherein the vertical member supports a light-sensing element for receiving light reflected transversely from the vertical beam by a beam splitter supported by the vertical member. The vertical beam passing through the beam splitter passes through a window or filter in a cap mounted on the header and covering the light-emitting element, the light-sensing element, the beam splitter, and the vertical member. Substantially all of the transversely reflected light impinges on the light-sensing element and can be used to control the power to the light-emitting element. A simple lens can by used to collimate the beam. Interior portions of the unit are formed from light absorbing materials such as black ceramic, black plastic, anodized aluminum, etc. The combined effect of the non-reflective interior of the assembly, the orientation of the photo-diode to have an acceptance cone perpendicular to the beam axis, the small entrance pupil, and the optical filter reduces ambient radiation in the unit by as much as −75 dB of the level outside the device. This reduces noise and drift in the automatic power control loop to produce constant intensity in the output light beam.
Abstract:
This invention provides a solar simulator measurement method capable of high-accuracy measurements with fast-response photovoltaic devices as well as with slow-response photovoltaic devices, and a solar simulator for implementing the method. A flash having a pulse waveform with a flattened peak is generated from a xenon lamp 1. The flash is sensed by an irradiance detector 3, its irradiance measured, and the irradiance of the light source is adjusted to fall within a prescribed narrow range based on the detected irradiance value. Then, the flash with irradiance within the prescribed range irradiates photovoltaic devices 4 under measurement, and the current and the voltage output by the photovoltaic devices 4 are measured at multiple points while a load of the photovoltaic devices 4 is controlled. This process is repeated with multiple flashes to obtain an I-V curve for the photovoltaic devices.
Abstract:
A test socket, a test system and methods of testing an image sensor or other optically interactive device. The test system may include a light source for illuminating the image sensor device. A diffuser may be provided to scatter the light. A test socket may include an area configured for receiving the image sensor device. The image sensor device may be in electrical communication with a printed circuit board. The diffuser may be positioned within the test socket or affixed to the printed circuit board. Optionally, the diffuser may provide support for the image sensor device, or a seat of at least partially optically clear material may provide support for the image sensor device. In another embodiment, a test socket includes a seat of at least partially optically clear material enabling collimated light or diffused light to reach the image sensor device.
Abstract:
A chopped radiation source composed of a radiation source component, a chopping component and an optical fiber connector component. Each of these components is arranged within a housing in a manner such that the elements of each of these components will not move in an unintended manner during use.
Abstract:
A device for measuring optical power simultaneously for two or more spectral regions. Two or more photodetectors, such as photodiodes, measure the pulse energy and/or power emitted by a laser having output in two or more spectral regions. The laser radiation is transmitted through a diffuser or beamsplitter, then filtered and/or attenuated so that light from each respective spectral region is incident on the active region of a photodiode. The device also includes electronic circuitry with one or more operational amplifiers for each photodiode, integrators and analog-to-digital converters. In a preferred embodiment, the device also includes a microprocessor to provide noise reduction and calibration functions for each photodiode output, and to drive a display or readout.
Abstract:
An apparatus and method for video imaging the spatial response of radiation-responsive devices, such as photomultiplier tubes. The apparatus probes the device under-test with an array of radiation emitting elements, such as light-emitting diodes, programmed with a scanning sequence such that the device under-test output response, e.g., the anode current of a photomultiplier tube, may serve as a video signal to a video display device such as a television or monitor. A video image so produced provides a map of the spatial response of the radiation-responsive device which may indicate perturbances, flaws, and inhomogeneities in the spatial responsivity of the device.
Abstract:
A validatable method for determining a photochemically effective dose for inactivating pathogens in a fluid sample is described herein. In particular, the instant invention covers methods for determining a photochemically effective dose sufficient to inactivate pathogens in a biological sample while leaving biologically active substances of interest unaffected. A batch irradiation reactor effective for inactivating pathogens in biological samples is also described.
Abstract:
An emitting source capable of radiating substantial energy in the near infrared spectrum and suitable for use in non-dispersive infrared gas analyzers or other devices is described. Operation can be steady state (DC) or pulsed at high frequency with excellent modulation characteristics. The device consists of a tungsten filament mounted across the pins of a small transistor outline header and centered at the focal point of a parabolic or other shaped reflector. The header assembly is enclosed by a resistance-welded cap and window assembly having a specially sealed sapphire or other suitable IR transmissive window. Fundamental to the operation of the inventive IR emitter is the incorporation of a getter within the header package configured to prevent oxidation degradation of the tungsten filament. An inert gas backfill limits filament evaporation and further extends apparatus lifetime.
Abstract:
A light source for examining sites in heating, ventilating, and air conditioning systems for leaks using a fluorescent dye is described. The light source can include a low voltage lamp or a low heat generating lamp.
Abstract:
A desired color of illumination of a subject is achieved by determining settings for color inputs and applying those setting to one or more systems that generate and mix colors of light, so as to provide combined light of the desired character. In the examples of appropriate systems, an optical integrating cavity diffusely reflects light of three or more colors, and combined light emerging from an aperture of the cavity illuminates the subject. System settings for amounts of the different colors of the input lights are easily recorded for reuse or for transfer and use in other systems.