A radiometer had been designed for precision coherent radiation measurements and tested for long-term repeatability at wavelengths of 488 and 633 nm. The radiometer consists of a single high-quality PN silicon photodiode maintained in a nitrogen atmosphere with a quartz window designed to eliminate interference problems. Ratio measurements between the radiometer and an absolute type detector were made over a period of 215 days. At 0.5 mW, the standard deviations were 0.008 and 0.009 % at 488 and 633 nm respectively. The maximum deviations from the mean were 0.016 and 0.015 % at the respective wavelengths. The high precision, simplicity, and portability of the radiometer make it an excellent transfer standard for radiometric measurements.

Date Published: 26 September 1989
PDF: 7 pages
Proc. SPIE 1109, Optical Radiation Measurements II, (26 September 1989);

Published in SPIE Proceedings Vol. 1109:
Optical Radiation Measurements II
James M. Palmer, Editor(s)