Spontaneous parameter down-conversion is exploited as a tool for absolute quantum efficiency calibration of photon detectors working in the photon-counting regime. This paper innovatively proposes a quantum efficiency correction model by analyzing the effects of after-pulse, double channel bandwidth matching and other factors on double channel coincidence counting. This experimental system shows the minimum deviation of quantum efficiency is 0.17% and detector quantum efficiency calibration accuracy better than 1.23%. The development of this new radiation calibration technology will play an important role in the future space radiation reference source and high-precision satellite radiation calibration, quantum communication and low-light level fields, environmental monitoring and climate research programs.
Spontaneous parameter down-conversion is exploited as a tool for absolute quantum efficiency calibration of photon detectors working in the photon-counting regime. This paper innovatively proposes a quantum efficiency correction model by analyzing the effects of after-pulse, double channel bandwidth matching and other factors on double channel coincidence counting. This experimental system shows the minimum deviation of quantum efficiency is 0.17% and detector quantum efficiency calibration accuracy better than 1.23%. The development of this new radiation calibration technology will play an important role in the future space radiation reference source and high-precision satellite radiation calibration, quantum communication and low-light level fields, environmental monitoring and climate research programs.
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 new calibration method of detectors can be realized by using correlated photons generated in spontaneous parametric down-conversion (SPDC) effect of nonlinear crystal.An absolute calibration system of detector quantum efficiency is performed.And its principle and experimental setup are introduced.A continuouswave (CW) ultraviolet (351 nm), diode-pumped, frequency-doubled, and solid-state laser is used to pump BBO crystal.The quantum efficiencies of the photomultiplier at 633, 702, and 789 nm are measured respectively.The coincidence peaks are observed using coincidence circuit.Some measurement factors including the filter bandwidth of trigger channel, the detector position alignment and polarization of the pump light are analyzed.The uncertainties of this calibration method are also analyzed, and the relative uncertainties of total calibration are less than 5.8%.The accuracy of this method could be improved in the future.
With the aim to realize Quantum Efficiency(QE) measurement of photon detectors based on Spontaneous Parametric Down-conversion(SPDC),two type of coincidence count systems were set up,the correction factors of coincidence count were analyzed and the real experimental methods of correction factors were given.Firstly,the principle of SPDC and the technique using SPDC to calibrate the QE of photo detectors were introduced.Then the design of two type of coincidence count systems,gated dual-photon counter coincidence count system and TAC/MCA coincidence count system,were introduced.Finally,the main correction factors,accidental coincidence,missing coincidence,dead time of counters and detectors were analyzed,and the calculation and test methods were also given.Experimental results show that the deviation between this two type of coincidence setups is less than 0.4% after correction,which indicates that the two setups can satisfy the requirement of QE measurement.
There are two general methods in radiometric calibration of detectors, one is based on radiation sources and the other based on detectors. Because the two methods need to establish a primary standard of high precision and a transfer chain, precision of the standard will be reduced by extension of the chain. A new calibration method of detectors can be realized by using correlated photons generated in spontaneous parametric down-conversion (SPDC) effect of nonlinear crystal, without needing transfer chain. Using 351.1-nm output of a tunable laser to pump 'beta'-barium borate (BBO) crystal, an absolute calibration experimental system of single photon detectors based on correlated photons is performed. The quantum efficiency of photomultiplier (PMT) at 702.2 nm is measured by the setup. Advantages of this method over traditional methods are also pointed out by comparison.
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.
Spontaneous parametric down conversion has been largely exploited as a tool for absolute calibration of photon counting detectors, photomultiplier tubes or avalanche photodiodes working in the Geiger regime. In this work we investigate the extension of this technique from very low photon flux of the photon counting regime to the absolute calibration of analog photodetectors at higher photon flux. Moving towards a higher photon rate, i.e. at a high gain regime, the spontaneous parametric down conversion shows the intrinsic limitations of the method, while the stimulated parametric down conversion process, where a seed beam is properly injected into the crystal in order to increase the photon generation rate in the conjugate arm, allows us to work around this problem. A preliminary uncertainty budget is discussed.