A continuously tunable far-IR Raman laser has been used to measure the responsivity and the spectral response of uncoated LiTaO3 pyroelectric detectors between 230 and 530 μm. A striking feature of the spectral response curves is a periodic sequence of maxima and minima, with a modulation factor of ≥75%. Calculations based on the theory of an absorbing Fabry-Perot etalon indicate that these variations correspond to interference fringes produced by multiple reflections at the surfaces of the LiTaO3 crystal.
© 1989 Optical Society of America
Wen-sen Zhu, Jerald R. Izatt, and B. K. Deka, "Pyroelectric detection of submicrosecond laser pulses between 230 and 530 µm," Appl. Opt. 28, 3647-3651 (1989)