Abstract: An optical and infrared periscope includes a housing having an elongated 35 degree prism mounted in its upper portion in a position to receive a light image and refract and reflect the image toward a lower portion of the housing. The prism has a first portion of an optical grade glass that transmits and reflects light in a visible range of the light spectrum and a second portion of an optical grade single crystal silicon that transmits and reflects light in a range of wavelengths of from about three microns to about five microns. An HgCdTe focal plane array is provided in the lower portion of the housing for receiving the image reflected by the second portion of the prism and producing output signals representing the reflected image. The lower portion of the housing also contains an electronics package for processing the output signals and displaying a visible image on a cathode ray tube, which may be viewed through an eyepiece.