We investigated the properties of various light fields based on the Hanbury-Brown-Twiss(HBT)experiment consisted by two single-photon-counting modules(SPCMs),one 50/50beam splitter and the Fast-Com P7888card.Having experimentally investigated the second-order degree of coherence g2(τ)for the continuous-wave and the pulse lasers and the single-photon source generated by single atom,we confirmed the experiment results by theoretical analysis.Specially,we have achieved a high quality of single-photon source based on single atom trapped in the magnetic-optical trap and the far-off-resonance trap with g(2)(τ=0)=0.09and g(2)(τ=0)=0.08,respectively.Using the pulse laser and the single atom,we can perform the triggered single photon experiment.
Non-photon-number-resolving single-photon-counting modules (SPCM's), also called on-off photon detectors, have been used in quantum optics for investigating the properties of various light fields based on the Hanbury-Brown-Twiss (HBT) experiment. However, for different incident light fields the experimental conditions can affect the measured photon statistics. In this paper, the second-order degree of coherence
g(2), known as the important factor for quantitying a single-photon source, is experimentally investigated by means of the HBT scheme consisting of two SPCM's. By comparing the results of coherent field with that of the thermal field, we show that the measured
g(2) is affected by the photon-counting rate and the resolution time from pulsed to continuous wave fields. The proper counting rate and resolution time for characterizing the exact photon statistical properties of input fields are determined.
The second-order degree of coherence of pseudo-thermal light and coherence time are experimentally studied via the Hanbruy-Brown-Twiss (HBT) scheme. The system consists of two non-photon-number-resolving single- photon-counting modules (SPCMs) operating in the Geiger mode. We investigate the coherence time of the incident beam for different spot sizes on a ground glass and speeds of a rotating ground glass. The corresponding coherence time can be obtained from Gaussian fitting for the measured second-order degree of coherence. The results show that the coherence time of measured pseudo-thermal light depends on the spot sizes and the rotating speeds of the ground glass. The maximum value of the second-order degree of coherence is reduced as the rotating speed decreases. This result can be well explained by the model of mixed thermal and coherent fields with different ratios.