The Optimum Detector Aperture in Photon Correlation Spectroscopy Experiments
Hui Yang, Gang Zheng and Meng Chao Li
In Photon Correlation Spectroscopy (PCS), it is important to keep the detector area smaller than the coherence area. However, only a little research has been devoted to ascertaining how small the detector aperture should be. This paper focuses on determining the optimum aperture for the first time in the following ways. The signal in the PCS experiment is produced using spatial coherence and the quantum noise is developed by photon statistics. By calculating the signal-to-noise power ratio (S2/N2) of the Photon Multiplier Tube, the optimum detector aperture is calculated as the best S2/N2. Furthermore, the best signal to noise power ratio can also be obtained by adjusting the distance between the pin holes.