PURPOSE To determine corneal Q value and its related factors in Chinese subjects older than 30 years. DESIGN Cross sectional study. METHODS 1,683 participants (1,683 eyes) from the Handan Eye Study were involved, including 955 female and 728 male with average age of 53.64 years old (range from 30 to 107 years). The corneal Q values of anterior and posterior surfaces were measured at 3.0, 5....

Given a three-dimensional surface G, not necessarily rotationally symmetric, and away from a point source, we design a surface F such that the lens sandwiched between the two surfaces refracts radiation into a given direction or into a given point. The surface F satisfies a system of first-order partial differential equations that can be solved in terms of G and the refractive indices of the me...

The recent developments of our method to design two freeform optical surfaces (either refractive or reflective) using an optimized ray mapping computation are presented. The procedure is based on the Monge-Kantorovich theory of optimal mass transport, and the related conditions for an optimal mapping. The procedure is illustrated by designing an efficient street lighting lens, achieving an opti...

In this paper, we show that broadband spectral data can be experimentally extracted from corrugated metallic surfaces consisting of a linear array of subwavelength grooves supporting tightly confined spoof plasmons. Using a combination of the scattering edge coupling method and short-time Fourier transform, we are able to discern the group velocity characteristics of a spoof plasmon pulse, whic...

Shape from Polarization (SfP) estimates surface normals using photos captured at different polarizer rotations. Fundamentally, the SfP model assumes that light is reflected either diffusely or specularly. However, this model is not valid for many real-world surfaces exhibiting a mixture of diffuse and specular properties. To address this challenge, previous methods have used a sequential soluti...

Today’s internet-focused communication industry is driving a powerful transition from slower electronic systems to high-speed all-optical systems. A central effort is the miniaturization and integration of photonic devices into highly functional optical circuits. New processing and packaging technologies are now required that can precisely shape and assemble optical components to sub-wavelength...

Microscopic fluorescent samples of interest to cell and molecular biology are commonly embedded in an aqueous medium near a solid surface that is coated with a thin film such as a lipid multilayer, collagen, acrylamide, or a cell wall. Both excitation and emission of fluorescent single molecules near film-coated surfaces are strongly affected by the proximity of the coated surface, the film thi...

Vision loss due to corneal injuries or diseases can be treated by transplantation of human corneal grafts (keratoplasty). However, quality assurance in retrieving and cultivating the tissue transplants is confined to visual and microbiological testing. To identify previous refractive surgery or morphological alterations, an automatic, noncontact, sterile screening procedure is required. Twenty-...

─ It is currently believed that nanometerscale internal refractive index fluctuations within biological cells change significantly during the initial stages of ultra early-stage cancer development well in advance of these changes becoming more pronounced and histologically detectable. Here, backscattered cepstral results of photonic nanojet-illuminated cells are investigated as a means to offer...

Metamaterials can be designed to operate at frequencies from the visible to the mid-IR, making these structures useful for both refractive index sensing and surface-enhanced infrared absorption spectroscopy. Here we investigate how the mechanical deformation of compliant metamaterials can be used to create new types of tunable sensing surfaces. For split ring resonator based metamaterials on po...