Kam Wai Clifford Chan

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Two week-long studies in 1982-1983 have measured ambient concentrations of polycyclic aromatic hydrocarbons (PAH) and phthalate esters in air in both the particulate and gas phase along the U.S.-Canadian border and the Niagara River. Concentrations of the PAH species monitored varied from 3 pg m-3 to 40 ng m-3. PAH’s with three rings or less were found in(More)
We show theoretically that high-order thermal ghost imaging has considerably higher visibility and contrast-to-noise ratio than conventional thermal ghost imaging, which utilizes the lowest-order intensity cross correlation of the object and the reference signal. We also deduce the optimal power order of the correlation that gives the best contrast-to-noise(More)
The practical use of a grazing x-ray telescope is demonstrated for hard-x-ray imaging as hard as 40 keV by means of a depth-graded d-spacing multilayer, a so-called supermirror. Platinum-carbon multilayers of 26 layer pairs in three blocks with a different periodic length d of 3-5 nm were designed to enhance the reflectivity in the energy range from 24 to(More)
We present a theoretical comparison of the signal-to-noise characteristics of quantum versus thermal ghost imaging. We first calculate the signal-to-noise ratio of each process in terms of its controllable experimental conditions. We show that a key distinction is that a thermal ghost image always resides on top of a large background; the fluctuations in(More)
Quantum lithography (QL) has been suggested as a means of achieving enhanced spatial resolution for optical imaging, but its realization has been held back by the low multiphoton detection rates of recording materials. Recently, an optical centroid measurement (OCM) procedure was proposed as a way to obtain spatial resolution enhancement identical to that(More)
Petros Zerom,1 Kam Wai Clifford Chan,2 John C. Howell,3 and Robert W. Boyd1,3,4 1Institute of Optics, University of Rochester, Rochester, New York 14627, USA 2Rochester Optical Manufacturing Company, 1260 Lyell Avenue, Rochester, New York 14606, USA 3Department of Physics and Astronomy, University of Rochester, 500 Wilson Boulevard, Rochester, New York(More)
We compare the performance of high-order thermal ghost imaging with that of conventional (that is, lowest-order) thermal ghost imaging for different data processing methods. Particular attention is given to high-order thermal ghost imaging with background normalization and conventional ghost imaging with background subtraction. The contrast-to-noise ratio(More)
We present a theoretical analysis of the properties of an unseeded optical parametic amplifier (OPA) used as the source of entangled photons for applications in quantum lithography. We first study the dependence of the excitation rate of a two-photon absorber on the intensity of the light leaving the OPA. We find that the rate depends linearly on intensity(More)