Domain-engineered thin-film LiNbO<sub>3</sub> pyroelectric-bicell optical detector

Abstract

We have fabricated a bicell detector consisting of a single freestanding film of single-crystal lithium niobate (LiNbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) 10-μm thick, having two adjacent domains of opposite spontaneous polarization, and hence, two adjacent pyroelectric detector regions of equal and opposite sensitivity. The film was created by applying the process of crystal ion slicing and electric field poling (domain engineering) to a Z-cut LiNbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> wafer. The detector's noise equivalent power was 6 nW/spl middot/Hz/sup -1/2/ at 16 Hz, and the ambient temperature-dependent variation of the detector's response near room temperature was 0.1% K/sup -1/. The acoustic noise sensitivity measured at 100 Hz was -24 dB relative e to that of a single-domain detector.