The laps uses photo excitation of the semiconductor to probe the surface potential at the insulator - electrolyte interface . the semiconductor is addressed by a modulated flux of ( infrared ) photons : this flux results in the generation of hole - electron pairs in the semiconductor Laps的原理是基于电场效应使器件对绝缘层与电解质溶液间界面电位变化敏感，其结构类似于eis (电解质?绝缘层?半导体)结构，它的特殊之处在于用光对半导体进行照射引起电解质?绝缘层界面间电位的变化。
