Integrating infra-red detector with electronically modulated response

A new integrating IR detector exhibits equivalent dark currents as low as 1.2 × 10¿15 A/cm2. Signal integration takes place in the bulk of a semiconductor photosensitive element. The ultralow dark current permits very long integration and storage times. Integration times longer than 12 h are reported. IR response beyond the usual low field cutoff is observed and shown to depend strongly on the applied electric field. This allows voltage-controlled starting and stopping of in situ signal integration beyond the low field cutoff wavelength.