Laser energy measurements with a liquid absorption cell

The suggestion that the volume expansion of the liquid in an absorption cell calorimeter can provide an instantaneous record of the energy in a laser pulse is examined. Experiments with a cell of effective length 8 cm using a 5% solution of nickel sulphate are described. Because of the temperature dependence of the cubical coefficient of expansion, sensitivity depends on the starting temperature and the variation of displacement with energy is nonlinear. A pulse calibration technique is suggested and justified by comparative experiments with a nickel-copper cone calorimeter.