We demonstrate metamaterial metal-based bolometers, which take advantage of
resonant absorption in that a spectral and/or polarization filter can be built
into the bolometer. Our proof-of-principle gold-nanostructure-based devices
operate around 1.5 \mum wavelength and exhibit room-temperature time constants
of about 134 \mus. The ultimate detectivity is limited by Johnson noise,
enabling room-temperature detection of 1 nW light levels within 1 Hz bandwidth.
Graded bolometer arrays might allow for integrated spectrometers with several
octaves bandwidth without the need for gratings or prisms and for integrated
polarization analysis without external polarization optics
