Integrated Broad Band Optical Calibration Sources for Star Simulation

Current calibration techniques do not permit pre-flight, in-flight, or real time calibration. The available optical calibration sources such as lamps and blackbody simulators are bulky, can be used only in laboratory conditions and require precise adjustments of the total flux, color, and spectral shape, accomplished by using filters, diaphragms, mirrors, lenses and software to perform complicated calculations to calibrate the data. The objective of this project is development, fabrication, and testing of miniature high-stability integrated super broadband optical emission sources for field and in-flight calibration of stellar photometers and spectrometers. In order to meet this objective we will utilize results in the area of Silicon Carbide and Si-based avalanche Light Emitting Diodes achieved by Integrated Micro Sensors Inc, in order to develop more efficient and mature devices of this type based on III nitride materials. This effort will be based on the new developments in III nitride materials growth, characterization, and processing accomplished by the Center for Advanced Materials (University of Houston). The high stability of the proposed devices in a wide temperature range, including cryogenic temperatures and vacuum environments, will be provided by employment of the avalanche electroluminescence process based on intra-band hot electron transitions. BENEFIT: High stability of the proposed devices in a wide temperature range, including cryogenic temperatures and vacuum environments, will be provided by employment of the avalanche electroluminescence process based on intra-band hot electron transitions. High performance and super-broad spectral range will result from implementation of improved quality more efficient direct bandgap materials and bandgap-engineered structures, as well as employment of advanced processing methods. The extended emission spectrum ranging from at most 280 nm to at least 1770 nm, will be achieved using broad-band emissions from tuned III nitride-based avalanche LED structures and their combinations, integrated on a single chip. Individual addressing of each LED in the structure will allow for spectral simulation of a large variation of different class stars.