Meghan D Duncan

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We have constructed a spatially scanning coherent anti-Stokes Raman spectroscopic (CARS) apparatus that allows us to image the distribution of distinct chemical species in a microscopic sample region. Images of onion-skin cells have been obtained by using the CARS signal produced by the 2450-cm(-l) band of deuterated water. Future applications will be(More)
We report direct experimental evidence of the absence of exponential gain at the Stokes wavelength for Stokes/anti-Stokes phase-matched stimulated Raman scattering. The amplification of a Stokes seed pulse was measured at various propagation angles relative to the pump direction. Nonexponential growth was observed at the Stokes/ anti-Stokes phase-matching(More)
We use optical coherence tomography with a new configuration to determine the size and location of subsurface defects in solid ceramic and composite ceramic materials. Cross-sectional subsurface regions either parallel or perpendicular to the surface were examined. We present experimental results showing that the size and distribution of small subsurface(More)
We have used a newly developed Yb-doped high-power fiber source in an optical coherence tomography (OCT) apparatus. We have analyzed various properties of interest for OCT measurements such as spectral shape, related gate width, central wavelength, bandwidth, and power output.
We propose the use of stimulated Raman scattering for time-gated image amplification and demonstrate its use for the detection of images through a strongly scattering material. Using 30-ps pulses from a frequency-doubled Nd:YAG laser, we have amplified and detected images through a suspension of nondairy creamer with a spatial resolution of less than 300(More)
A method is described for measuring various laser beam characteristics with modest experimental complexity by digital processing of the near and far field images. Gaussian spot sizes, peak intensities, and spatial distributions of the images are easily found. Far field beam focusability is determined by computationally applying apertures of circular or(More)
A previous audit revealed a high frequency of adult fingers visualised on neonatal intensive care unit (NICU) chest radiographs-representing an example of inappropriate occupational radiation exposure. Radiation safety education was provided to staff and we hypothesised that the education would reduce the frequency of adult fingers visualised on NICU chest(More)
We have used optical coherence tomography to study the internal structure of a variety of non-biological materials. In particular, we have imaged internal regions from a commercial grade of lead zirconate titanate ceramic material, from a sample of single-crystal silicon carbide, and from a Teflon-coated wire. In each case the spatial positions of internal(More)