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A unique detection system has been developed which allows for the counted implantation of individual low-energy heavy ions into silicon. This system can ensure the placement of individual ions at precise locations within a wafer using an EBL-machined resist mask, and utilizes the generation of ionization within the silicon substrate to allow for the reliable detection of 31 P + implants down to 14 keV. Due to the necessity for low-noise operation, it is important that both the capacitance of the detectors and their leakage current be reduced as much as possible. To this end, we have now created a detector architecture with a measured capacitance of 0.6 pF and sub-pA leakage current at liquid nitrogen temperature, which has allowed us to achieve a resolution of 410 eV (44.2 electrons RMS) when coupled to low-noise signal-processing electronics and operated at 90 K. [ABSTRACT FROM AUTHOR]

We report on the fabrication and characterization of the first accelerometer based on a polymer optical fiber Bragg grating (FBG) for operation at both 850 and 1550 nm. The devices have a flat frequency response over a 1-kHz bandwidth and a resonance frequency of about 3 kHz. The response is linear up to at least 15 g and sensitivities as high as 19 pm/g (shift in resonance wavelength per unit acceleration) have been demonstrated. Given that 15 g corresponds to a strain of less than 0.02% and that polymer fibers have an elastic limit of more than 1%, the polymer FBG accelerometer can measure very strong accelerations. We compare with corresponding silica FBG accelerometers and demonstrate that using polymer FBGs improves the sensitivity by more than a factor of four and increases the figure of merit, defined as the sensitivity times the resonance frequency squared. [ABSTRACT FROM PUBLISHER]