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Dr. James M. Palmer passed away on Thursday, January 4, 2007 after a courageous battle with cancer. His book, The Art of Radiometry, by James M. Palmer and Barbara G. Grant, is available from SPIE Press: http://spie.org/x648.html?product_id=798237 ISBN: 9780819472458. Vol: PM 184. 393 pages. Hardcover.
Contact Information: Ms. Cindy Gardner, Administrative Associate. Telephone: 520-621-3035. E-mail: cindy@optics.arizona.edu
Dr. Palmer's Faculty Web site: http://www.optics.arizona.edu/faculty/Resumes/Palmer.htm |
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The charter of the radiometry laboratory at the Optical Sciences Center includes the measurement of optical properties of materials and devices, the development of new methods to measure optical radiant power and energy, and the performance of radiometric measurements and calibrations. The laboratory is under the direction of Dr. James M. Palmer.
A Cary 14 spectrophotometer has been updated and rebuilt for making transmission and reflectance measurements. The original source has been replaced with a tungsten-halogen lamp with high-efficiency collection optics. The monochromator wavelength drive has been automated and placed under computer control. The exit optics have been replaced with a single-beam sampling system which uses a common path for all optical measurements. The beam used for transmission measurements is highly collimated, and the sample holder provides for measurements of transmission vs. angle of incidence. Several samples can be measured at normal incidence in a single run. An integrating sphere attachment is being designed and built to make relative diffuse reflectance measurements as a function of both wavelength and incidence angle. Absolute measurements will also be made on selected materials. This instrument is patterned after similar instruments at NIST, NRCC and NPL. The estimated capabilities are shown below:
WAVELENGTH RANGE 250-2750 nm
WAVELENGTH UNCERTAINTY 0.2 nm
SPECTRAL BANDPASS 1nm - 10nm
TRANSMISSION UNCERTAINTY 0.05% FS (1)
DETECTORS AVAILABLE Silicon, TE-cooled Ge & InGaAs
A radiometric blackroom with several interesting features is located in the Precision Radiometry laboratory at the Optical Sciences Center . The source room is separated from the main blackroom for optimum control over stray light. Sources include tungsten-halogen lamps, infrared glowers and blackbody simulators, and various arc sources, all with appropriate stabilized and regulated power supplies. A small (60 mm diameter) collimator is available to provide a parallel beam into the blackroom. A 2-meter optical rail projects into the blackroom to allow accurate source-detector distance determination. A turntable is used for angular measurments. Several calibrated tungsten-halogen lamps from NIST and commercial vendors are available. Two precision double monochromators with prism dispersers are available for spectral measurements. A filter wheel with filters covering the wavelength range 400-2500 nm is also present. Instrumentation includes two electrically-calibrated pyroelectric radiometers, an electrically-calibrated laser power meter and an electrically-calibrated pyrheliometer. Detector standards include three QED-100 absolute silicon detectors and two QED-200 absolute silicon detectors which have had subsequent calibration to the 0.05% uncertainty level by NPL (UK). Computerized data collection and processing equipment are also included in this facility. This laboratory was assembled in the early '80's and was among the first to participate in the absolute self-calibration of detectors, corroborating the initial measurements at NBS (now NIST) and supplying scattering data to validate the specular reflectance measurements.
We have an instrument that was designed to measure the thermo-optic coefficient (change of index of refraction with temperature) of optical materials. The wavelength range is from 200 nanometers to 30 micrometers. We have measured over a temperature range from 10K to 400K. The nominal uncertainties in index are n/1E04 and the temp coefficient is within 1%. Precision refractometry at room temperature in the visible is done with a Wild precision spectrometer with visible line sources. The nominal uncertainties are less than 0.001% with this instrument. Details can be found on a separate page.