Broadband Radiometric LED Measurements

Published: September 07, 2016

Author(s)

George P. Eppeldauer, Catherine C. Cooksey, Howard W. Yoon, Leonard M. Hanssen, Vyacheslav B. Podobedov, Robert E. Vest, Uwe Arp, Carl C. Miller

Abstract

At present, broadband radiometric measurements of LEDs with uniform and low-uncertainty results are not available. Currently, either spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V-lambda function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the broadband radiometric LED measurement procedure we suggested before. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed.
Proceedings Title: Fifteenth International Conference on Solid State Lighting and LED-based Illumination Systems
Volume: 9954
Conference Dates: August 28-September 1, 2016
Conference Location: San Diego, CA
Conference Title: SPIE Optics + Photonics: Optical Engineering + Applications Symposium
Pub Type: Conferences

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Keywords

LED, LED radiometric measurement, broadband LED measurement, integrated radiometric quantities, LED integrated irradiance, UV-LED measurement, blue LED measurements, red LED measurements, flat-response LED radiometer, pyroelectric LED meter, filtered-Si LED meter
Created September 07, 2016, Updated February 19, 2017