The ability to accurately measure the mobility of particles at low concentrations in small volumes is very
useful for a broad range of applications. The coupling of micro- and nano-fluidic devices and confocal microscopy
offers an efficient and rapid technique for multiplexed single molecule detection and analysis. Microfluidic channels
at micron and sub-micron scales were designed and fabricated on fused silica wafers. Fluorescence correlation
spectroscopy and fluorescence lifetime were applied to measure and analyze the mobility of fluorescent species in
micro-droplets, micro-channels, and nano-channels. The experimental results show
Radiation detector capable of discriminating between different species of high energy ions is of great demand by aerospace and high energy physics communities. We propose the optical fiber-based real time ion detector and discriminator, which can have long lifetime in radiation environment, can be compact and low production cost. The basis of detector's principle of operation is the strong dependence of the pattern of energy dissipation with ion penetration depth in the matter on the type of the ion. Another key phenomenon enabling our fiber optic based detector is the refractive index change in optical fiber in the vicinity of particle track due to the dissipated energy. These two effects provide the opportunity to measure the energy dissipation versus penetration depth as well as total energy released simultaneously in real time with a single detector. Thus, different types of ions can be distinguished by measuring total energy dissipated and energy dissipation versus distance. To discriminate between ions species we propose to use measurement of the Bragg peak position. Total energy dissipated by the particle in the detector material and determination of the Bragg peak position gives the full information on the kind of the incident ion as confirmed via simulations.
We present the use of swept wavelength interferometry for distributed fiber-optic temperature measurements in a
Nuclear Reactor. The sensors consisted of 2 m segments of commercially available, single mode optical fibers. The
interrogation technique is based on measuring the spectral shift of the intrinsic Rayleigh backscatter signal along the
optical fiber and converting the spectral shift to temperature.