Abstract:
An integrating sphere cover covering an integrating sphere having a light receiving entrance is provided and includes a first casing and a fixing assembly. The first casing partially covers the integrating sphere and includes a first opening where the light receiving entrance passes. A curvature radius of the first casing is greater than that of the integrating sphere. The fixing assembly is disposed at the first casing, and the first casing is fixed to the integrating sphere through the fixing assembly. The first casing or the fixing assembly includes a nozzle. When the first casing covers the integrating sphere, a first interval communicating with the first opening and the nozzle is between the first casing and the integrating sphere to form a first hollow intermediate layer. An air flow passes through the first hollow intermediate layer via the nozzle and the first opening. An integrating sphere module is also provided.
Abstract:
The stabilization of a light-emitting diode (LED) calibration standard includes a light-emitting diode (LED), or an array of LEDs; a cylindrical hood surrounding the LED; an interior baffle for keeping the light output of the LED, and ambient light from behind the LED, from escaping to the other side; a photodetector for receiving the light output of the LED and generating a signal proportional to luminous output; and a hood surrounding the photodetector. A variable current source receives the signal and stabilizes the LED light output by adjusting the operating current of the LED to maintain a constant light output from the LED.
Abstract:
The averaged pulse energy (J) of a Pulsed Type Laser Source can be measured by several types of commercial laser energy meters, such as pyroelectric detector or thermopile sensor, the spectral responsivity and the time/frequency related response properties of which are compatible with those of the Pulsed Type Laser Source. These Commercial Laser Energy Meters, regardless of sensor/detector type, should be calibrated against the working standards calibrated in a national (or an international) traceability chain relying on primary standards on the highest level having the lowest uncertainty in realizations of the fundamental SI units. FCIS based-LEMCS designed in this invention accomplishes both of the above proficiencies of measuring the averaged pulse energy of the Pulsed Type Laser Source and calibrating the Commercial Laser Energy Meters, which are traceably to primary level standards. FCIS based-LEMCS contains an integrating sphere having a novel port and an interior design and a series of mechanical choppers having separate Duty Cycles, each of which is rotated by an electrical motor in FCIS based-LEMCS, used for generating a chopped type laser, called as Chopped Type Laser Source, in order to provide the reference and averaged pulse energy for traceable calibration of Commercial Laser Energy Meters. With this invention, in addition to generating the reference and averaged pulse energy to be used during the calibration of Commercial Laser Energy Meters to be performed by means of FCIS based-LEMCS, the peak pulse energies of the Pulsed Type Laser Source and the Chopped Type Laser Source, which is a strict part of FCIS based-LEMS and which is used for producing the reference averaged pulse energy in the calibration of Commercial Laser Energy Meters, are also measured by FCIS based-LEMCS, traceable to Electrical Substitution Cryogenic Radiometer (ESCR) in primary optical watt scale (W), to 133Cs (or 87Rb) Atomic Frequency Standard in time scale t (s), and to direct current unit (A) realized with Quantum Hall—primary resistance standard (ohm) and DC Josephson primary voltage standard (V). With this configuration presented as a preferred embodiment, the averaged pulse energy measurements are performed and achieved for a range extending from 16.5 p J to 100 mJ.
Abstract:
An optical system comprising a randomizer that has a plurality of randomly positioned scatterers for scattering and thereby randomizing light to generate a speckle pattern and a detector for detecting the speckle pattern to determine at least one property of the light and/or change in at least one property of the light.
Abstract:
A lighting dome that can be used to inspect semiconductor wafers can include a small aperture, backlighting, a reflectance gradient and/or a broad spectrum light source.
Abstract:
A calibration device for a radiometer includes an integrating cavity and a honeycomb blackbody mounted to the integrating cavity. A plurality of emitters are mounted to the exterior rim of the integrating cavity for transmitting narrow band wavelengths of light into and out of the integrating cavity. A controller, selectively, activates one or more emitters to radiate a single narrow band wavelength of light during an ON period and turn OFF during another period. A plurality of reference detectors are also mounted to the exterior rim of the integrating cavity for measuring the intensity of each narrow band radiation outputted from the integrating cavity. The reference detectors are effective in determining changes in intensity output by each of the narrow band emitters from the integrating cavity. The measured changes in intensity outputted by the emitters are used to calibrate the radiometer with the changes traced back to a NIST standard.
Abstract:
Disclosed is a method of generating a correction function for a light-emitting diode (LED) testing process. The method comprises the steps of: detecting light emitted by a reference LED and reflected from one or more inactive LEDs on a panel within a field of view of a detector, a number of said inactive LEDs within the field of view being varied such that uncorrected values of at least one optical parameter are derivable as a function of the number of inactive LEDs in the field of view; detecting light emitted by the reference LED, or by an active LED having identical optical properties to the reference LED, in the absence of any other LEDs, to determine at least one reference value for the or each said optical parameter; and calculating differences between the uncorrected values and the or each reference value to generate the correction function, the correction function being based on the number of inactive LEDs which are arranged within the field of view of the detector when the detector detects light emitted by an LED under test.
Abstract:
An apparatus may have a light source configured to generate light, a reflector configured to collect the light and direct the light in a desired direction, a spectral filter assembly configured to receive the light from the reflector. The spectral filter assembly may have a stationary frame and a plurality of filter elements supported by the stationary frame. Filter elements of the plurality of filter elements may simultaneously filter a desired quantity of light within wavelength band to provide a filtered output light beam. A homogenizer may be configured to receive the filtered output light beam and produce a homogenized light beam having a substantially uniform irradiance distribution across a cross-section of the homogenized light beam.
Abstract:
Systems and methods for accurately measuring the luminous flux and color (spectra) from light-emitting devices are disclosed. An integrating sphere may be utilized to directly receive a first portion of light emitted by a light-emitting device through an opening defined on the integrating sphere. A light collector may be utilized to collect a second portion of light emitted by the light-emitting device and direct the second portion of light into the integrating sphere through the opening defined on the integrating sphere. A spectrometer may be utilized to measure at least one property of the first portion and the second portion of light received by the integrating sphere.
Abstract:
Systems and methods for measuring an intensity characteristic of a light beam are disclosed. The methods include directing the light beam into a prism assembly that includes a thin prism sandwiched by two transparent plates, and reflecting a portion of the light beam by total-internal-reflection surface to an integrating sphere while transmitting the remaining portion of the light beam through the two transparent plates to a beam dump. The method also includes detecting light captured by the integrating sphere and determining the intensity characteristic from the detected light.