Abstract: A device for reflecting electromagnetic energy comprises a solidified foam mass which has reflector agents embedded therein for reflecting at least one frequency of electromagnetic energy. The frequency or frequencies of electromagnetic energy reflected are within the region of the electromagnetic spectrum utilized for radar signaling, the infrared region, the visual region or within any combination of those regions. A variety of dyes are used for reflecting frequencies within the infrared region of the electromagnetic spectrum and a variety of phosphorous compounds are utilized for reflecting frequencies within the infrared region of the electromagnetic spectrum. Radar energy is reflected by a multitude of discreet electrically conducting elements or dipoles of a length approximately equal to one-half (1/2) the wave length of the radar energy to be reflected which dipoles are distributed in an approximately uniform manner throughout the mass during the formation of the foam mass.

Abstract: A heterodyne laser detection system includes a local oscillator laser, an infrared light detector positioned to receive light transmitted through a receiving window and also from the local oscillator laser and to generate heterodyne signals in response thereto. An oscillator controller repeatedly sweeps the frequency of the local oscillator laser to ensure that the laser signal being sought generates heterodyne signals within the limited passband of an intermediate frequency amplifier. Upon detecting heterodyne signals amplified by the intermediate frequency amplifier above a defined threshold, the oscillator control switches to control the local oscillator laser to track the detected laser signal such that the heterodyne signals remain within the passband of the intermediate frequency amplifier.