Applications of optical trapping to single molecule DNA

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project focused on the methodologies required to integrate optical trapping with single molecule detection (SMD) so as to demonstrate high speed sequencing through optical micromanipulation of host substrates, nucleotide cleavage, and single molecule detection. As part of this effort, the new technology of optical tweezers was applied to the confinement and manipulation of microsphere handles containing attached DNA fragments. The authors demonstrated substrate optical trapping in rapid flow streams, the fluorescence excitation and detection of fluorescently labeled nucleotides in an optical trapping system, and the epifluorescent imaging of DNA fragments in flow streams. They successfully demonstrated optical trapping in laminar flow streams and completely characterized the trapping process as functions of fluid flow velocity, chamber dimension, trapping depth, incident laser power, and fluorescence measurement geometry

Five-channel polymer waveguide wavelength division demultiplexer for the near infrared

A five-channel wavelength division demultiplexer (WDDM) fabricated in polymer gelatin waveguides and operating over a 100-nm bandwidth centered at 770 nm in the near infrared is discussed. The device has a maximum diffraction efficiency of 80% at 730 nm, has a spectral bandwidth of 17+or-3 nm per channel, and effectively utilizes a portion of the large optical transparency bandwidth ( approximately 2400 nm) of the photo-lime gelatin polymer material at laser diode wavelengths. High-channel-density WDDM devices at longer infrared wavelengths should be possible.<

INFLUENCE OF SURFACE CORRUGATIONS ON SURFACE ELECTROMAGNETIC WAVES

Ce papier présente la preuve expérimentale de l'influence de l'uniformité des profils d'un réseau sur le couplage des ondes électromagnétiques de surface et les courbes de dispersion de ces ondes lorsqu'elles se propagent sur des surfaces à échelons périodiques.We present experimental evidence of the influence of grating profile uniformity on surface electromagnetic wave (SEW) coupling and dispersion curves for SEWs propagating on periodically corrugated surfaces