Linearity of Fast and Highly Sensitive LiTaO$_{3}$ Pyroelectric Detectors in the Terahertz Range

In response to single-cycle THz pulses, we measured the linearity parameter of lithium tantalate pyroelectric detectors, over nearly three orders of magnitude in pulse energy, up to 2  $\mu$ J. The response was linear up to 1  $\mu$ J pulse energy and 25  $\mu$ J/cm $^{2}$ energy flux, and sublinear at higher irradiations. This finding shows the importance of characterizing the detector response linearity for accurate THz metrology. The detectors had high sensitivity in single-pulse detection mode up to 10 kHz repetition rate.