Abstract: In an uncooled camera having a focal plane array and an optical lens for focusing radiation from infrared radiation sources onto the focal plane array, the improvement comprising providing a thermochromic optical switch for blocking radiation from an extremely hot infrared radiation source from reaching the focal plane array.

Abstract: The invention applies wavefront coding to the front of an electro-optic/infrared device to minimize the amount of light which is retroreflected by systems, such as Fowarding Looking Infrared systems, back to its source. The invention (unlike conventional reduction methods) does not rely on reducing the laser power leaving the interrogated sensor, but primarily on controlling its direction. A sensor according to the present invention, which has been wavefront coded for reduction of reflected light, will also effect the direction of the scattered light, thereby significantly reducing that which returns to the zero bistatic angle position. In contrast, a limitation of conventional methods is that once specular reflections are addressed, the remaining retroreflected signal typically results from scattered light at the focal plane which is largely collected and recollimated by the system optics.

Abstract: A light sensor protection system and method protects a light sensor system from a laser threat. The light sensor system has a sensor housing which contains optical elements disposed within the sensor housing and at a first end of the housing to converge light rays entering the housing at a focal plane. A focal plane array is disposed within the sensor housing substantially coincident with the focal plane. A means for protecting the light sensor system from a laser threat is disposed within the housing remote from the optical elements, the light rays, and the focal plane array. The method includes the steps of (a) providing a light sensor system as described above; and (b) protecting the light sensor system from a laser threat in the presence of a laser threat or upon a warning thereof with the means for protecting the light sensor system from a laser threat.

Abstract: A light sensor protection system and method protects a light sensor system from a laser threat. The light sensor system has a sensor housing which contains optical elements disposed within the sensor housing and at a first end of the housing to converge light rays entering the housing at a focal plane. A focal plane array is disposed within the sensor housing substantially coincident with the focal plane. A means for protecting the light sensor system from a laser threat is disposed within the housing remote from the optical elements, the light rays, and the focal plane array. The method includes the steps of (a) providing a light sensor system as described above; and (b) protecting the light sensor system from a laser threat in the presence of a laser threat or upon a warning thereof with the means for protecting the light sensor system from a laser threat.

Abstract: The invention applies wavefront coding to the front of an electro-optic/infrared device to minimize the amount of light which is retroreflected by systems, such as Fowarding Looking Infrared systems, back to its source. The invention (unlike conventional reduction methods) does not rely on reducing the laser power leaving the interrogated sensor, but primarily on controlling its direction. A sensor according to the present invention, which has been wavefront coded for reduction of reflected light, will also effect the direction of the scattered light, thereby significantly reducing that which returns to the zero bistatic angle position. In contrast, a limitation of conventional methods is that once specular reflections are addressed, the remaining retroreflected signal typically results from scattered light at the focal plane which is largely collected and recollimated by the system optics.

Abstract: A technique for internal forward looking infrared (FLIR) system detection laser pulses. For scanning systems image pixel output of each frame is sampled as image data which is used to determine a pattern of saturated image pixels. The pattern of saturated image pixels is compared to predetermined laser pulse patterns and is then analyzed to determine if a laser pulse was detected. For staring systems, the patterns are compared to previous and following frames to determine if short lived large changes occur to determine if a laser pulse was detected.

Abstract: An arrangement and technique for reduced laser induced damage threshold (T) of a sacrificial optical element within an electro-optical system without increased system reflectivity. A sacrificial optical element including input and output surfaces is located normal to the optical axis at an intermediate focal plane of the system and a micro-prism structure is also present on at least one of the surfaces.

Abstract: A system and technique to incorporate threat detectors within the FLIR's ical train and use the radiation reflected off of insertable protective filters, or a coated clear window, to determine if the threat is still present. If there has been some change in laser threat status then there is allowed the removal or insertion of the protective filter.

Abstract: Enclosure sign device for unavoidable viewing of a sign before manipulation f an entryway opening device. An enclosure of an entryway opening device includes at least one side surface extending out at least as far as the entryway opening device, a back surface coupled to the side surface to accommodate the entryway opening device through the back surface, and a front surface releasably coupled to the side surface which can be releasably opened or closed over the entryway opening device. The enclosure is coupled to a surrounding surface of the entryway opening device and includes a display for releasably holding a sign attached to the outside surface of the front surface so that sign viewable when the front surface is closed. Access is obtained to an entryway opening device by releasably opening the latching so that there is unavoidable viewing of a sign before manipulation of the entryway opening device.