Calorimeter with compensative absorber for measuring mu W level laser power

摘要

A calorimeter with a compensative absorber developed for measuring mu W-level laser power is described. With this calorimeter, laser power measurements can be made irrespective of pressure fluctuations in the surroundings. The calorimeter was found to be very effective in reducing the effects of ambient pressure fluctuations. The pressure stability has been improved by more than tenfold, and the standard deviation of the measured value is 0.01 approximately 0.6% for 10-mW approximately 1- mu W power levels. The systematic error of the measurement, which is represented by the standard deviation (1 sigma ), was evaluated as +or-0.1% for 10 mu W.