光子探测通常是要求高灵敏度的光学测量所要选择的方法.因为用近于皮秒的时间分辨率方法很容易实现单光子探测,这种方法应用的领域很广,诸如半导体检验,细菌和癌症探测、共焦显微镜和高能物理等.如果光子达到很高频率或信号具有限定的寿命,就要求探测器具有高带宽、高增益和高灵敏度.只有光电倍增管具有这种功能,它具有较大的面积,且容易得到.这种光电倍增管中的新型负电子亲和势光电阴极在可见光谱波段量子效率可达40%,从而使光子—电子间的转换灵敏度极高. Photon detection is usually the method of choice for high-sensitivity optical measurements because single-photon detection is very easy to achieve with picosecond time-resolution methods, such as semiconductor inspection, bacteria and cancer detection , Confocal microscopy and high-energy physics, etc. If photons reach very high frequencies or the signal has a finite life expectancy, detectors are required to have high bandwidth, high gain and high sensitivity. Only PMTs have this function, which has a larger Area and are readily available.The new negative-ion-affording photocathodes in this photomultiplier tube have quantum efficiencies of up to 40% over the visible spectral band, resulting in extremely high sensitivity of photon-electron transitions.