Instruments for the measurement of infrared radiation (IR) are becoming increasingly important for a variety of commercial and non-commercial applications. An example of such an application is a night vision surveillance system. A night vision system is capable of producing a visible image of an object or objects in darkness, based upon the infrared radiation level of the object or objects. Conventional night vision systems, however, have various shortcomings. Existing night vision image intensifiers, for example, cannot operate in total darkness: they generally require low-level ambient light, such as starlight, to convert an infrared radiation image of an object to a visible display. Many conventional night vision systems also require intervening electronics to convert the absorbed infrared radiation to a visible display. Traditional night vision technologies include cryogenically cooled infrared cameras, uncooled infrared cameras, image intensification tubes and low light level, solid-state, charge coupled devices. Charge coupled devices (CCD) are also unable to operate in total darkness. Cryogenically cooled infrared cameras require a costly cryogenic cooling system and while uncooled infrared cameras may ultimately be operable in total darkness, they would still require special packaging, temperature stabilization systems, camera electronics, and a display, each of which adds costs to the night vision system.
The present invention is directed to overcoming the shortcomings of the conventional technology, and the costs associated with the supplemental systems required in the conventional technology, by providing an infrared imager which converts infrared radiation directly to a visible image.