Abstract: An array of diffraction grating coupled infrared photodetectors is coupled to corresponding high-speed amplifiers for creating a multiple channel high speed receiver for an optical communication system. Each photodetector includes a three-dimensional diffractive resonant optical cavity formed by a diffraction grating that resonates over a narrow range of wavelengths. By creating different resonant optical cavities, the receiver detects each optical channel individually, thereby simplifying receiver design. The receiver finds ready application in systems based upon high power CO2 lasers and semiconductor lasers such as quantum cascade lasers allowing extremely long line of sight communication, such as between satellites. Other applications include ship to ship or ground to missile communications. These applications will benefit from increased jamming resistance and security.

Abstract: A diffraction grating coupled infrared photodetector for providing high performance detection of infrared radiation is described. The photodetector includes a three-dimensional diffractive resonant optical cavity formed by a diffraction grating that resonates over a range of infrared radiation wavelengths. By placing a limited number of p/n junctions throughout the photodetector, the photodetector thermal noise is reduced due to the reduction in junction area. By retaining signal response and reducing the noise, the sensitivity increases at a given operating temperature when compared to traditional photovoltaic and photoconductive infrared photodetectors up to the background limit. The photodetector device design can be used with a number of semiconductor material systems, can form one- and two-dimensional focal plane arrays, and can readily be tuned for operation in the long wavelength infrared and the very long wavelength infrared where sensitivity and noise improvements are most significant.

Abstract: A two-color photodetector for detecting two different bands of infrared radiation is described. The photodetector includes either a diffractive resonant optical cavity that resonates at the two colors of interest, or a diffractive resonant optical cavity that resonates at the first color and a vertical resonant optical cavity that resonates at the second color. By placing materials that absorb only one of the two colors at the appropriate locations within the resonate structure, the resultant signals include little cross-talk due to the opposite color. The two-color photodetector finds use in applications covering a wide portion of the infrared spectrum.

Abstract: A variable bandgap infrared absorbing material, Hg1-x Cdx Te, is manufactured by use of the process termed MOCVD-IMP (Metalorganic Chemical Vapor Deposition-Interdiffused Multilayer Process). A substantial reduction in the dislocation defect density can be achieved through this method by use of CdZnTe layers which have a zinc mole fraction selected to produce a lattice constant which is substantially similar to the lattice constant of HgTe. After the multilayer pairs of HgTe and Cd0.944Zn0.056Te are produced by epitaxial growth, the structure is annealed to interdiffuse the alternating layers to produce a homogeneous alloy of mercury cadmium zinc telluride. The mole fraction x in Hg1-x(Cd0.944Zn0.056)xTe can be varied to produce a structure responsive to multiple wavelength bands of infrared radiation, but without changing the lattice constant. The alloy composition is varied by changing the relative thicknesses of HgTe and Cd0.944Zn0.056Te.

Abstract: A variable bandgap infrared absorbing material, Hg.sub.1-x Cd.sub.x Te, is manufactured by use of the process termed MOCVD-IMP (Metalorganic Chemical Vapor Deposition-Interdifffused Multilayer Process). A substantial reduction in the dislocation defect density can be achieved through this method by use of CdZnTe layers which have a zinc mole fraction selected to produce a lattice constant which is substantially similar to the lattice constant of HgTe. After the multilayer pairs of HgTe and Cd.sub.0.944 Zn.sub.0.056 Te are produced by epitaxial growth, the structure is annealed to interdiffuse the alternating layers to produce a homogeneous alloy of mercury cadmium zinc telluride. The mole fraction x in Hg.sub.1-x (Cd.sub.0.944 Zn.sub.0.056).sub.x Te can be varied to produce a structure responsive to multiple wavelength bands of infrared radiation, but without changing the lattice constant. The alloy composition is varied by changing the relative thicknesses of HgTe and Cd.sub.0.944 Zn.sub.0.056 Te.

Abstract: A growth vessel (10) comprises a crucible (12) for containing the source materials within its cavity (26), a substrate carrier (15, 115) positioned on inner shoulder 27 of the crucible sidewalls (22-25), a source tray (14) positioned within the crucible cavity (26), at least one spacer (13) positioned between the bottom of the crucible cavity (26) and the source tray (14), a substrate carrier (15, 115) positioned within the crucible cavity (26) for mounting a substrate parallel to the source of growth material in the source tray (14), and a crucible lid (17, 117).