Fabrication and evaluation of a freestanding pyroelectric detector made from single-crystal LiNbO_3 film

We have packaged a rectangular $3 \mathrm{mm}\times 4 \mathrm{mm}$, $10‐\mathit{\mu }\mathrm{m}$-thick Z-cut lithium niobate $\left({\mathrm{LiNbO}}_3\right)$ film produced by crystal ion slicing (CIS) and evaluated its performance as a pyroelectric optical detector. We justify the difficulty of preparing the film by showing that the freestanding detector has much greater sensitivity than the same detector bonded to a substrate. We compare the sensitivity of three CIS-film detectors with that of a detector based on a $230‐\mathit{\mu }\mathrm{m}$-thick ${\mathrm{LiNbO}}_3$ plate and describe the detectors’ spatial uniformity and noise-equivalent power.