We report testing of the new absolute method of photodetector calibration based on the difference-signal measurement for two-mode squeezed vacuum by comparison with the traditional absolute method based on coincidence counting. Using low-gain parametric downconversion, we have measured the quantum efficiency of a counting detector by both methods. The difference-signal method was adapted for the counting detectors by taking into account the dead-time effect.
© 2011 Optical Society of America
Original Manuscript: December 22, 2010
Revised Manuscript: February 24, 2011
Manuscript Accepted: February 28, 2011
Published: April 5, 2011
I. N. Agafonov, M. V. Chekhova, T. S. Iskhakov, A. N. Penin, G. O. Rytikov, and O. A. Shcherbina, "Absolute calibration of photodetectors: photocurrent multiplication versus photocurrent subtraction," Opt. Lett. 36, 1329-1331 (2011)