Pyroelectric response to single infrared laser pulses in triglycine sulphate and strontium-barium niobate

Expressions are derived for the pyroelectric (PE) voltage response to single ir laser signals much shorter than the thermal time constant τT of the PE sample. It is shown both analytically and experimentally that when the electronic time constant τe is much shorter than the time characteristics of the signal, then the response exactly follows the signal and has a peak voltage Vp proportional to the load resistance RL. In the opposite case, the response rises as long as the signal persists, reaching a peak value proportional to absorbed energy but independent of RL, then decays exponentially with falltime τe ∝ RL, as long as τe≪τT.