Fascinating colors of diamonds are generated by a combination of mechanisms including Fresnel reflection, volume absorption and light dispersion. This paper proposes an approach to unify these mechanisms to synthesize realistic computer images of diamonds. Our work is based on a composite spectral model that accounts separately for smooth components and spikes in spectra. While sufficiently han...

We report a broad-band continuum light source with high power, low noise and a smooth spectrum centered at 1.15 mum for ultrahigh-resolution optical coherence tomography (OCT). The continuum is generated by self-phase modulation using a compact 1.059 mum femtosecond laser pumping a novel photonic crystal fiber, which has a convex dispersion profile with no zero dispersion wavelengths. The emiss...

Chung, Haejun MSECE, Purdue University, December 2013. Time Domain Simulation With Novel Photovoltaic Materials. Major Professor: Peter Bermel. Thin-film silicon-based solar cells have operated far from the Shockley-Queisser limit in all experiments to date. Novel light-trapping structures, however, may help address this limitation. Finite-difference time domain simulation methods offer the pot...

The use of Cepheids as distance indicators on Galactic and extragalactic distance scales is based upon the Cepheid period luminosity (PL) and period luminosity colour (PLC) relations. These relations are usually derived in terms of the properties of Cepheids at mean light – i.e. averaged over their pulsation cycle. In this paper, we derive a physical argument for the existence of PL and PLC rel...

We have systematically investigated the wideband slow light in two-dimensional material graphene, revealing that graphene exhibits much larger slow light capability than other materials. The slow light performances including material dispersion, bandwidth, dynamic control ability, delay-bandwidth product, propagation loss, and group-velocity dispersion are studied, proving graphene exhibits sig...

We demonstrate a novel technique to determine the size of Mie scatterers with high sensitivity. Our technique is based on spectral domain optical coherence tomography measurements of the dispersion that is induced by the scattering process. We use both Mie scattering predictions and dispersion measurements of phantoms to show that the scattering dispersion is very sensitive to small changes in ...

The use in silicon photonics of the new optical materials developed in soft matter science (e.g. polymers, liquids) is delicate because their low refractive index weakens the confinement of light and prevents an efficient control of the dispersion properties through the geometry. We experimentally demonstrate that such materials can be incorporated in 700 μm long slot photonic crystal waveguide...

A novel technique for the noninvasive measurement of tissue optical properties simultaneously at all visible and near-infrared wavelengths is presented. The technique is based on the time-resolved detection of multicolor diffusely scattered light. Short pulses of white light are produced by using self-phase modulation by focusing the light from a short-pulsed high-power laser into a cuvette fil...

Chromatism causes great quality degradation of the imaging system, especially for diffraction imaging. The most commonly method to overcome chromatism is refractive/diffractive hybrid optical system which, however, sacrifices the light weight and integration property of diffraction elements. A method through compensation between the structure dispersion and material dispersion is proposed to ov...

A theoretical investigation is made of the effects of dispersion in neutral gases on the formation of white-light fringes in an ideal Mach-Zehnder interferometer. It is found that the shift of the brightest fringe is determined by the change of the group refractive index at an effective mean wavelength of the white light. However, the white-light fringe technique may be used to measure changes ...