Most LADAR (laser radar, LIDAR) imaging systems use pixel-basis sampling, where each azimuth and elevation resolution element is uniquely sampled and recorded. We demonstrate and examine alternative sampling and post-detection processing schemes where recorded measurements are made in alternative bases that are intended to reduce system power consumption and laser emissions. A prototype of such a sensor having the capability to generate arbitrary illumination beam patterns rather than spot, line scanning, or flash techniques is described along with computational imaging algorithms to reduce speckle and identify scene objects in a low-dimensional compressed basis rather than in the pixel basis.
View Article and Find Full Text PDFWe present the concept and experimental results for Spectral LADAR, an augmented LADAR imager combining three-dimensional (3D) time-of-flight ranging with active multispectral sensing in the shortwave infrared (1080-1620 nm). The demonstrated technique is based on a nanosecond regime pulsed supercontinuum transmitter and spectrally multiplexed receiver that computes a high-resolution range value for each of 25 spectral bands. A low frame-rate prototype unit is described.
View Article and Find Full Text PDFWhile microcantilevers offer exciting opportunities for mechano-detection, they often suffer from limitations in either sensitivity or selectivity. To address these limitations, we electrodeposited a chitosan film onto a cantilever surface and mechano-transduced detection events through the chitosan network. Our first demonstration was the detection of nucleic acid hybridization.
View Article and Find Full Text PDFThe patterning of nanoparticles represents a significant obstacle in the assembly of nanoscale materials and devices. In this report, cysteine residues were genetically engineered onto the virion surface of tobacco mosaic virus (TMV), providing attachment sites for fluorescent markers. To pattern these viruses, labeled virions were partially disassembled to expose 5' end RNA sequences and hybridized to virus-specific probe DNA linked to electrodeposited chitosan.
View Article and Find Full Text PDFWe report a new approach for microfluidic optical bioanalysis that is based on the electrically driven assembly of bio-components on a transparent sidewall and the optical detection of the assembled components using planar waveguides. This allows localized electrical signals for bio-assembly and optical signals for bio-detection that can easily be applied in MEMS systems. We demonstrate a BioMEMS design incorporating this scheme and its output signal when using fluorescent detection.
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