We have designed and tested a 500‐psec‐rise‐time pyroelectric detector. The responsivity is great enough to drive a Tektronix 519 oscilloscope when amplified with a 1.0‐GHz‐bandwidth amplifier. To obtain broad spectral response we have developed a thermally fast‐absorbing black which has approximately 50% absorption from 0.3 &mgr; to greater than 50 &mgr;, and transfers 90% of the absorbed energy to the pyroelectric crystal in 400 psec. The maximum detector output voltage prior to amplification is 2. 0 V, limited by the absorbing black's burn intensity.