Domain-engineered pyroelectric radiometer

We built a large-area domain-engineered pyroelectric radiometer with high s patial and spectral response uniformity that is an excellent primary transf er standard for measurements in the near- and the mid-infrared wavelength r egions. The domain engineering consisted of inverting the spontaneous polar ization over a 10-mm-diameter area in the center of a uniformly poled, 15.5 mm x 15.5 mm square, 0.25-mm-thick LiNbO3 plate. Gold black was used as th e optical absorber on the detector surface, and an aperture was added to de fine the optically sensitive detector area. Our results indicate that we si gnificantly reduced the acoustic sensitivity without loss of optical sensit ivity. The detector noise equivalent power was not exceptionally low but wa s nearly constant for different acoustic backgrounds. In addition, the dete ctor's spatial-response uniformity variation was less than 0.1% across the 7.5-mm-diameter aperture, and reflectance measurements indicated that the g old-black coating was spectrally uniform within 2%, from 800 to 1800 nm. Ot her detailed evaluations of the detector include detector responsivity as a function of temperature, electrical frequency response, angular response, and field of view. OCIS codes: 040.0040, 120.5630, 230.0230.