We explore the nature of the classical propagation of light through media with strong frequency-dependent dispersion in the presence of a gravitational field. In the weak field limit, gravity causes a redshift of the optical frequency, which the slow-light medium converts into a spatially varying index of refraction. This results in the bending of a light ray in the medium. We further propose e...

A passive imaging polarimeter records the polarization state of light reflected by an object that is illuminated with an unpolarized and usually uncontrolled source. Passive polarimetric imagery has shown to be useful in many remote sensing applications including shape extraction, material classification and target detection/recognition. In this paper, we present an image segmentation algorithm...

PURPOSE Childhood accommodation interferes with accurate diagnosis of the latent refractive errors. Dynamic retinoscopy offers accurate measurements of accommodative response, while an autorefractometer can predict the accommodative system activation in children. A correlation of the accommodative effort with the dynamic refraction has been investigated in emmetropic children, before and after ...

This paper describes a shape from shading technique for the reconstruction of specular surfaces based on refraction and color illumination or multiple pulsed light sources. The technique is used to retrieve the small-scale shape of waveundulated water surfaces in the laboratory and the field.

When capturing images underwater, image formation is affected in two major ways. First, the light rays traveling underwater are absorbed and scattered depending on their wavelength, creating effects on the image colors. Secondly, the glass interface between air and water refracts the ray entering the camera housing because of a different index of refraction of water, hence the ray is also affec...

AIMS To examine prospectively the recovery of various parameters after discontinuation of overnight orthokeratology. METHODS Seventeen subjects undergoing orthokeratology for 12 months were examined. Refraction, corneal topography, wavefront aberrometry, a visual acuity test and a contrast sensitivity test were performed at baseline, 12 months after commencement of the procedure, and 1 week a...

Diffraction enhanced imaging (DEI) is a new, synchrotron-based, x-ray radiography method that uses monochromatic, fan-shaped beams, with an analyser crystal positioned between the subject and the detector. The analyser allows the detection of only those x-rays transmitted by the subject that fall into the acceptance angle (central part of the rocking curve) of the monochromator/analyser system....

An all-dielectric coaxial waveguide that can overcome problems of polarization rotation and pulse broadening in the transmission of optical light is presented here. It consists of a coaxial waveguiding region with a low index of refraction, bounded by two cylindrical, dielectric, multilayer, omnidirectional reflecting mirrors. The waveguide can be designed to support a single mode whose propert...

We experimentally demonstrate the light focusing by negative refraction in a photonic crystal slab superlens at wavelengths lambda of 1.26-1.42 microm. The photonic crystal slab was fabricated on silicon-on-insulator substrate with an interface structure optimized for low reflection and diffraction losses. The light focusing in the photonic crystal slab was clearly observed through the intentio...