The fundamental principle of this system is as follows . divide the incident beam into two beams , one of which passing through variable optical delay ( vod ) , then combination of the two beams with the same amplitude and delay - superposition is sent to bi - photon detector and transformed into current signals , whose intensity is proportional to the intensity of bi - photon autocorrelation signals 本系统的主要原理是:把入射光分为两束,让其中一束光通过一个可调光纤延迟线,再把这两束具有相同幅度并延时重合的光合路后送进双光子探测器,该探测器同时吸收两个光子发生双光子效应从而产生电流信号,且其大小与双光子自相关信号的强度成正比。
