The present invention relates to an optical window-filter including a thermochromic material and a light absorbing material. An absorption of light by the light absorbing material generates heat that causes phase transformation of the thermochromic material. The present invention further relates to a filter for an infrared imaging system having detectors sensitive to radiation in an infrared transmission spectrum. The filter includes a thermochromic material and a light-absorbing material. An absorption of high-power radiation in the infrared transmission spectrum by the light-absorbing material generates heat that causes phase transformation of the thermochromic material to attenuate the high-power radiation while transmitting substantially unaffected low-power radiation in the infrared transmission spectrum.