CC BY
8ALT'22
THz-I-1
NONLINEAR AND TERAHERTS PHOTONICS
Towards standardless calibration of the quantum efficiency of analog
terahertz detectors
We consider a possibility of measuring the quantum efficiency of sensitive elements of terahertz detectors using quantum-correlated pairs of optical and terahertz photons. Such pairs are generated via the nonlinear-optical process of spontaneous parametric down-conversion (SPDC) in strongly frequency non-degenerate regime [1]. Nowadays, the SPDC method of absolute calibration [2] is successfully applied to optical single-photon detectors and CCD cameras in frequency degenerate regime [3,4], but its extension to the terahertz range requires some specific modification.
Virtually none of the currently used terahertz detectors has the single-photon detection property. At the same time, our analysis of statistical distributions of the analog readings of antenna-coupled terahertz superconducting bolometer in the terahertz SPDC channel reveals the discrete nature of terahertz detection [5]. Similar features are observed in histograms of an analog photomultiplier tube placed in the optical SPDC channel [6]. We propose a modified SPDC quantum efficiency calibration method based on approximation of the histograms and applicable to both analog and single-photon detectors. Experimental verification of the method is carried out in the optical range using degenerate SPDC. We show a fairly good matching between the input photon numbers measured by a single-photon avalanche diode calibrated using the standard photon-counting approach, and by an analog photomultiplier tube calibrated using the proposed method. This result opens a possibility to calibrate terahertz analog detectors as well. A possible experimental scheme and the whole calibration procedure are discussed.
The work was done under financial support of the Russian Science Foundation (Grant No. 22-12-00055).
[1] G.Kh. Kitaeva, A.A. Leontyev, P.A. Prudkovskii, Quantum correlation between optical and terahertz photons generated under multimode spontaneous parametric down-conversion, Phys. Rev. A 101, 053810 (2020).
[2] D.N. Klyshko, On the use of two-photon light for absolute calibration of photoelectric detectors, Sov. J. Quantum Electron. 10(9), 1112-1117 (1980).
[3] S.V. Polyakov, A.L. Migdall, High accuracy verification of a correlated photon-based method for determining photoncounting detection efficiency, Opt. Expr. 15, 1390-1407 (2007).
[4] A. Avella, I. Ruo-Berchera, I.P. Degiovanni, G. Brida, M. Genovese, Absolute calibration of an EMCCD camera by quantum correlation, linking photon counting to the analog regime. Opt. Lett. 41, 1841-1844 (2016).
[5] P. Prudkovskii, A. Leontyev, K. Kuznetsov, G. Kitaeva, Towards Measuring Terahertz Photon Statistics by a Superconducting Bolometer, Sensors 21, 4964 (2021).
[6] D.A. Safronenkov, N.A. Borshchevskaya, T.I. Novikova, K.G.Katamadze, K.A.Kuznetsov, G.Kh.Kitaeva, Optics Express 29, 36644-36659 (2021)
G.Kh. Kitaeva, P.A.Prukovskii, D.A. Safronenkov
Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991 Russia
