We review the geometrical-optics evolution of an electromagnetic wave propagating along a curved ray trajectory in a gradient-index dielectric medium. A Coriolis-type term appears in Maxwell equations under transition to the rotating coordinate system accompanying the ray. This term describes the spin-orbit coupling of light which consists of (i) the Berry phase responsible for a trajectory-dep...

We report on a new optics design for an optical coherence tomography (OCT) balloon imaging catheter. The design involves a miniature compound gradient-index (GRIN) rod lens, which consists of a fiber optic mode-field reducer and relay rod lenses to achieve predictable high lateral resolution at a desired large working distance. The compound lens design significantly simplifies the engineering p...

Current technology allows optical recording of brain activity in awake behaving mice through the use of miniature head-mounted microscopes. These images require processing, as they are unevenly illuminated, contain framewide shifts, and do not readily reveal individual neurons. After statistical methods yield a set of images containing putative individual neuron shapes and locations, a human mu...

We describe a new optical coherence tomography catheter-endoscope for micrometer-scale, cross-sectional imaging in internal organ systems. The catheter-endoscope uses single-mode fiber optics with a novel transverse scanning design. The distal end of the catheter-endoscope uses a gradient-index lens with a microprism to emit and collect a single spatial-mode optical beam with specific focusing ...

A MATLAB function that performs a direct numerical integration to the ray optics equation described in book Section 1.3.2 has been implemented. The code, which was written by Dennis Hancock http:nnwww.dennishancock.com, is embodied in the MATLAB function Launch Rays. The function launches a prescribed bundle of rays from a point on the z axis in a rectangular coordinate reference system. Each r...

We investigate the electron transport in smooth graphene pn junctions, generated by gradually varying electrostatic potentials. The numerically calculated coherent current flow patterns can be understood largely terms of semi-classical trajectories, equivalent to ones obtained for light beams a medium with changing refractive index. In energetically forbidden regions emerge, which increase refl...

An interference analysis for double-grating shearing interferometry called coherent gradient sensing is presented, and the results are compared with an earlier geometrical optics analysis and a Fourier optics analysis based on the Fresnel approximation. The influence of the order of approximation in these analyses and the equivalence of fringe interpretation in each case are discussed.