title: Absolute calibration of photodetectors: photocurrent multiplication versus photocurrent subtraction.
abstract: 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.
authors.affiliation: Physics Department, Moscow State University, Leninskiye Gory 1-2, Moscow 119991, Russia.
authors.forename: I N
authors.initials: IN
authors.lastname: Agafonov
authors.forename: M V
authors.initials: MV
authors.lastname: Chekhova
authors.forename: T S
authors.initials: TS
authors.lastname: Iskhakov
authors.forename: A N
authors.initials: AN
authors.lastname: Penin
authors.forename: G O
authors.initials: GO
authors.lastname: Rytikov
authors.forename: O A
authors.initials: OA
authors.lastname: Shcherbina