Calorimeters for pulsed lasers: calibration.

A calibration technique is developed and tested in which a calorimeter used for single-shot laser pulse energy measurements is calibrated with reference to a cw power standard using a chopped cw laser beam. A pulsed laser is required only to obtain the relative time response of the calorimeter to a pulse. With precautions as to beam alignment and wavelength, the principal error of the technique is that of the cw standard. Calibration of two thermopiles with cone receivers showed -2.5% and -3.5% agreement with previous calibrations made by the National Bureau of Standards.