Abstract: Disclosed is an infrared radiation (IR) sensor and imaging tube employing same wherein the sensor includes a pyroelectric substrate having a conductive layer of infrared radiation absorbing material on one surface thereof. An electron-emissive metallic grid is disposed on the opposite surface of the pyroelectric substrate and is configured to expose predefined discrete areas of the pyroelectric substrate at which radiation-dependent voltages are developed. These voltages permit the metallic grid to emit electrons in quantity proportional to the infrared radiation received by the radiation absorbing material and the pyroelectric substrate. This IR sensor may advantageously be incorporated in a thermal imaging tube which includes means for flooding the grid surface of the pyroelectric substrate with photons and means for accelerating electrons emitted therefrom to a suitable target, such as a charge coupled device (CCD), a phosphor, a silicon intensified target (SIT), or other suitable electron collector.