Research Of The Energy Loss Compensation Of High-energy Laser Energy Meter

With the high-energy laser extensively used in the domain of science, the accuracy of laser energy measurement become more important Because of some features of the absolute quantity thermal laser energy meter based on c onical cavity, for example, wide wavelength adaptation range, high laser damage threshold value and wide energy measurement range, which is used for the standard of the high-energy laser energy meter and extensively in the domain of the high energy laser measurement The conical cavity laser energy meter is based on quantity thermal theory, the conical cavity's temperature value rises after absorbing the laser energy, the temperature corresponding to the resistance value is gotten, and the energy value of laser can be obtained by measuring the resistance value of resistance wire which is winded on exterior surface of the absorbing cavity. However, laser energy will lose because of the heat exchange and the back scattering of the conical absorption cavity. Therefore, only after compensating and amending the loss, the exact measurement of the laser energy can be achieved.Aimed to the energy loss compensation problem of the conical cavity high-energy laser energy meter, firstly, resistance wire which is winded on exterior surface of the absorbing cavity and used in temperature measurement is experimental analyzed, the least square method is used to process experiment data of relationship between resistance and temperature of resistance wire and establish the compensation model to calibrate the character of calorimetric high-energy laser energy meter. By this method, resistance deviation between resistance wire and Pt100 is less than 0.01Ωand temperature deviation is less than 0.02℃, and the measurement accuracy of energy meter is great improved. Secondly, according to the heat transfer theory, the heat energy loss of the conical cavity due to the heat emission, the heat convection and the heat exchange are analyzed and the mathematical model of the heat energy loss are established, based on which the measurement result is curved fit utilizing the least squares technique and is compensated and amended utilizing the fitting curve, whose measurement repetitiveness' accuracy is larger than 0.7%, and the measurement repetitiveness is increased consumedly. Thirdly, according to the optics principles of reciprocity of the conical cavity inner face and the incident laser and utilizing complexification Simpson numerical method, the mathematical model of conical cavity jaw opening optical power density distribution and back scattering gross power is established, based on which the measurement result is compensated and "amended. The back scattering energy loss is about 0.5% to 2.5%. High-energy laser energy measuring accuracy is improved availably.