I will review recent advances in DoD nanoscience and technology (NST) at the Air Force Research Laboratory (AFRL) in the areas of nano-materials, nano-electronics, and nano-energetics. NST will profoundly change all critical aspects of maintaining a technologically superior national defense capability. In this talk, I will focus on programmatic priorities for AFRL basic and applied R&D in the seven selected priority areas that comprise the AFRL Strategic Nanotech Plan. The goal of this plan is to focus, prioritize and guide future AF funding in nanotechnology. The selected topics include: tailorable dielectrics, reconfigurable optical response materials, adaptive structural materials, quantum confined optical sensors and sources, nanotechnology for RF, as well as several cross-cutting topics such as self-assembly, interfaces, and modeling and simulation.
SHARC II is a background-limited 350 μm and 450 μm facility camera for the Caltech Submillimeter Observatory undergoing commissioning in 2002. The key component of SHARC II is a 12 × 32 array of doped silicon 'pop-up' bolometers developed at NASA/Goddard. Each 1 mm × 1 mm pixel is coated with a 400 Ω/square bismuth film and located λ/4 above a reflective backshort to achieve >75% absorption efficiency. The pixels cover the focal plane with >90% filling factor. At 350 μm, the SHARC II pixels are separated by 0.65 λ/D. In contrast to the silicon bolometers in the predecessor of SHARC II, each doped thermistor occupies nearly the full area of the pixel, which lowers the 1/f knee of the detector noise to <0.03 Hz, under load, at the bath temperature of 0.36 K. The bolometers are AC-biased and read in 'total power' mode to take advantage of the improved stability. Each bolometer is biased through a custom ~130 MΩ CrSi load resistor at 7 K and read with a commercial JFET at 120 K. The JFETs and load resistors are integrated with the detectors into a single assembly to minimize microphonic noise. Electrical connection across the 0.36 K to 4 K and 4 K to 120 K temperature interfaces is accomplished with lithographed metal wires on dielectric substrates. In the best 25% of winter nights on Mauna Kea, SHARC II is expected to have an NEFD at 350 μm of 1 Jy Hz<sup>-1/2</sup> or better. The new camera should be at least 4 times faster at detecting known point sources and 30 times faster at mapping large areas compared to the prior instrument.
We present the flight performance of the far infrared photometer (FIRP) onboard the infrared telescope in space (IRTS). The FIRP was designed to measure the absolute sky brightness in four submillimeter wavelength bands centered on 150, 250, 400, and 700 micrometer with a spectral resolution of lambda/(Delta) (lambda) equals 3, and with spatial resolution of 0.5 degrees. The bolometers were cooled to 300 mK by a <SUP>3</SUP>He refrigerator, and an ac bridge readout circuit was used to achieve high sensitivity. The <SUP>3</SUP>He refrigerator achieved a temperature of approximately 300 mK during each of three <SUP>3</SUP>He condensations carried out in orbit. The hold time was confirmed to be at least 7 days per cycle. We observed approximately 7% of the sky during a mission time of 3 weeks. Some excess noise was observed in most of the channels. Adequate sensitivity was achieved in all channels for observations at low galactic latitudes, where emission from interstellar dust is relatively bright. The preliminary sensitivities (60 sec integration, 1 (sigma) ) are estimated to be 7.7 multiplied by 10<SUP>-7</SUP>, 3.1 multiplied by 10<SUP>-8</SUP>, 7.7 multiplied by 10<SUP>-8</SUP>, and 3.7 multiplied by 10<SUP>-8</SUP> Wm<SUP>-2</SUP>sr<SUP>-1</SUP> for the 150, 250, 400, and 700 micrometer channels, respectively.
Conference Committee Involvement (1)
Nanostructure Integration Techniques for Manufacturable Devices, Circuits, and Systems: Interfaces, Interconnects, and Nanosystems