Single-photon detectors are widely used in modern quantum optics experiments and applications. Like all detectors, it is important for these devices to be accurately calibrated. A single-photon detector is calibrated by determining its detection efficiency; the common method to measure this quantity requires comparison to another detector. Here, we suggest a method to measure the detection efficiency of a single-photon detector without requiring an external reference detector. Our method is valid for individual single-photon detectors as well as multiplexed detectors, which are known to be photon number resolving. The method exploits the even-number photon-statistics of a nonlinear source, as well as the nonlinear loss of a single-photon detector that occurs when multiple photons are incident simultaneously. We have analytically modeled multiplexed detectors and used the results to experimentally demonstrate the calibration of a single-photon detector without the need for an external reference detector.
Single-photon detectors are widely used in modern quantum optics experiments and applications. Like all detectors, it is important for these devices to be accurately calibrated. A single-photon detector is calibrated by determining its detection efficiency; the common method to measure this quantity requires comparison to another detector. Here, we suggest a method to measure the detection efficiency of a single-photon detector without requiring an external reference detector. Our method is valid for individual single-photon detectors as well as multiplexed detectors, which are known to be photon number resolving. The method exploits the even-number photon-statistics of a nonlinear source, as well as the nonlinear loss of a single-photon detector that occurs when multiple photons are incident simultaneously. We have analytically modeled multiplexed detectors and used the results to experimentally demonstrate the calibration of a single-photon detector without the need for an external reference detector.
Calibration of fiber-coupled single-photon detectors usually requires knowledge of the input photon flux inside the fiber and/or knowledge of the linearity of a reference power meter. Many approaches have been presented in the past to accurately measure the photon detection probability of a single photon detector [1-6]. Under certain assumptions, one can utilize waveguide-coupled single photon detectors and a series of photon-counting measurements and a single-photon source to calibrate the detection efficiency of a single photon detector without the need of a reference power meter and the knowledge of the incoming photon flux. Here, this method is presented. Furthermore, if a reference detector is used, the detection efficiency of all evanescently coupled waveguide detectors can be measured, and the measurement outcome does not depend on splicing or fiber connection losses within in the setup, i.e., the measurement is setup-independent. In addition, the method, when using a reference detector, can be utilized to measure and distinguish between the absorption of a waveguide-coupled single photon detector and its internal detection efficiency. [1] A. J. Miller et al, Opt. Express 19, 9102–9110 (2011) [2] I. Muller et al., Metrologia 51, S329 (2014). [3] A. L. Migdall, Instrumentation and Measurement, IEEE Transactions on 50, 478–481 (2001). [4] S. V. Polyakov, A. L. Migdall, Optics Express 15, 1390–1407 (2007). [5] A. Avella et al., Optics Express 19, 23249–23257 (2011). [6] T. Lunghi et al., Opt. Express 22, 18078-18092 (2014)
Single-photon detectors are of great importance in spectroscopy, laser ranging, astronomy and wherever weak light detection is required, so a precise knowledge of their quantum efficiency is essential, but their calibration is by no means trivial. Traditional methods need a black body radiation source or a highly attenuated laser beam as a reference standard, or an already calibrated reference detector. It is well known that absolute measurement of the quantum efficiency, absolute in the sense that the calibration is independent of any radiometric standard or the properties of another detector, can be performed using entangled twin photons generated in optical spontaneous parametric down-conversion together with a reference detector. We have performed the first proof-of-principle experiment to determine the quantum efficiency by which no second detector or reference standard is required. This absolute self-calibration method is also based on the time correlation of photons emitted in parametric down-conversion, but with the introduction of a suitable time delay between the arrival times of the twin photons. Furthermore, we describe a scheme for absolute self-calibration of the quantum efficiency at different wavelengths by means of a pulsed source of nondegenerate down-converted photons. This method should have even greater potential for applications.
Single-photon detectors are finding increasingly wide application in all branches of science and technology thus a precise knowledge of their quantum efficiency is an essential prerequisite. We have performed the first proof-of-principle demonstration of a means to determine the quantum efficiency by which no second detector or reference standard is required. This absolute self-calibration method is based on the time correlation of entangled photons pairs emitted in spontaneous parametric down conversion. The measured quantum efficiency of a Si avalanche photodiode single-photon detector agrees well with the product specifications.
Single-photon detectors are of great importance in spectroscopy, laser ranging, astronomy and wherever weak light detection is required, so a precise knowledge of their quantum efficiency is essential, but their calibration is by no means trivial. Traditional methods need a black body radiation source or a highly attenuated laser beam as a reference standard, or an already calibrated reference detector. It is well known that absolute measurement of the quantum efficiency, absolute in the sense that the calibration is independent of any radiometric standard or the properties of another detector, can be performed using entangled twin photons generated in optical spontaneous parametric down-conversion together with a reference detector. We have performed the first proof-of-principle experiment to determine the quantum efficiency by which no second detector or reference standard is required. This absolute self-calibration method is also based on the time correlation of photons emitted in parametric down-conversion, but with the introduction of a suitable time delay between the arrival times of the twin photons. Furthermore, we describe a scheme for absolute self-calibration of the quantum efficiency at different wavelengths by means of a pulsed source of nondegenerate down-converted photons. This method should have even greater potential for applications.
A method for calibration of single-photon detectors without the need of input photon flux calibration is presented. The method relies on the use of waveguide-coupled single photon detectors and a series of photon-counting measurements using a single-photon source. It is shown that the method can yield relative uncertainties of less than 1% including counting statistics and fiber splice loss uncertainties with a total measurement time of about 1 h under the assumptions that the fractional losses of the waveguide-coupled detectors are known or zero and the loss along the waveguide is constant. It is also shown that the fractional losses of the waveguide-coupled detectors can be determined if they are equal. However, in this case an input photon flux calibration is required.
A nonclassical light source is used to demonstrate experimentally the absolute efficiency calibration of a photon-number-resolving detector. The photon-pair detector calibration method developed by Klyshko for single-photon detectors is generalized to take advantage of the higher dynamic range and additional information provided by photon-number-resolving detectors. This enables the use of brighter twin-beam sources including amplified pulse pumped sources, which increases the relevant signal and provides measurement redundancy, making the calibration more robust.