The experimental signal-to-noise ratios (S/N) of four photomultiplier light-detection systems are obtained for two values of the dc anode signal and dc anode dark current. The photodetection systems investigated are dc amplifier, lock-in, noise power, and combined lock-in plus noise power. Although there is no significant difference between the experimental S/N ratios of the noise power and lock-in-plus-noise-power system, they both produce significantly greater S/N ratios than the other methods. Theoretical S/N ratios are calculated assuming that shot noise only is present, and are compared with the corresponding experimental values.
RICHARD J. ANDERSON and J. CLEARY, "Detection of Weak Light Signals," J. Opt. Soc. Am. 60, 531-533 (1970)