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 τ_T of the PE sample. It is shown both analytically and experimentally that when the electronic time constant τ_e is much shorter than the time characteristics of the signal, then the response exactly follows the signal and has a peak voltage V_p proportional to the load resistance R_L. In the opposite case, the response rises as long as the signal persists, reaching a peak value proportional to absorbed energy but independent of R_L, then decays exponentially with falltime τ_e ∝ R_L, as long as ${\tau }_e{\mathrm{\ll \tau }}_T$ .