Optical density measurement of laser protection filters

Optical density D,defined as D=-log(transition light power Pt/total incident light power Pi),is one of important performance figures of laser eye protective glasses.In practice,it is defficult to make the measurement of parameter D>3.This paper proposed a measurement system including a laser source,double optical path subsystem,a data sampling and processing subsystem with computer.With the system,the case of parameter D>6 can be measured.