Research on laser energy measurement technology based on thermopile array

Abstract

To address the measuring requirements for ultra-large diameter and ultra-high laser energy in laser-driven inertial confinement fusion, a calorimetric method was employed for laser energy measurement. NB10 neutral absorption glass was used as the laser energy absorption material, and a temperature measurement system based on thermoelectric array was designed to establish the basic parts for laser energy measurement. Additionally, the thermal effects of pulse laser and continuous laser were simulated using finite element analysis, theoretically demonstrating the thermal effects for two forms of lasers are equivalent. Through meticulous design and testing, a apparatus was developed for calibrating laser energy meters. Measurement results indicated that the repeatability of this apparatus was better than 0.2%, capable of measurement of laser energies ranging from 300J to 11000J. This development is helpful for the research of laser-driven inertial confinement fusion.