A reference calorimeter for laser energy measurements

Principles and detailed procedures are described for measuring la se r energy and power in terms of e lectrica l e ne rgy based on voltage, resistance , and frequency standards. The construction of a sma ll isoperibol ca lorimetcr used for th e measurements is desc ribed. The ca lorimeter wi ll accommoda te 0.0] to 20.1 and 4 X 10 5 to I W cw and is limit ed to a maximum pul se intens it y of 0.1 .I/cm'. The s tandard deviation of comparison meas urements using two calorimeters and a beam s plitter is 0.08 percent when the s maller energy input is not less than 0. 3 1. The estimated limit s of sys temati c eITor for one ca lorim eter are 1.0 percent of the laser e ne rgy mea s ured by the calorimeter.