We present the selected results of theoretical and experimental investigations of high-performance ultra-thin
metamaterial-inspired absorbers designed for narrow-band operation at subterahertz frequencies and intended for
integration with spectrally-selective bolometric devices. The attainability of values up to 182 for the ratio of the free-space
wavelength to the absorber's thickness is experimentally demonstrated, while realizability of even thinner
structures is shown. The first prototypes of spectrophotometric and imaging detectors with metamaterial-based radiation-sensitive
pixels, utilizing a principle of THz-to-IR conversion, are discussed.