Research of backscattered laser energy within the energy measurement for large caliber high energy lasers

Backscattered laser energy profile is very important parameter in a cone-shaped laser energy meter because it affects the measurement precision of the instrument.From the reflection rule of laser in the surface of energy meter obeyed,the distribution function of power of laser beam in energy meter surface is deduced.Using the Simpson numerical calculation method,the distribution of laser power density in the opening of absorption body and the total backscattered laser power are obtained when the reflective index is fixed but the ratio of laser diameter and absorption cavity diameter is changed.The calculation results show that the backscattered energy loss is up to 0.5%~2.5% for a large caliber high energy laser.According to the backscattered laser power density profile,total backscattered laser energy can be gotten to compensate the measurement result,which will greatly improve the accuracy of high energy laser energy measurement.