SEPTEMBER 2010 CATARACT & REFRACTIVE SURGERY TODAY EUROPE 35 T he introduction of wavefront-sensing techniques to ophthalmology has redefined the clinical meaning of refractive error. Now, all imperfections in the components and materials within the eye that cause light rays to deviate from their desired path are referred to as optical aberrations. Lower-order aberrations (defocus and astigmati...

Multifocal vision corrections are increasingly used solutions for presbyopia. In the current study we have evaluated, optically and psychophysically, the quality provided by multizone radial and angular segmented phase designs. Optical and relative visual quality were evaluated using 8 subjects, testing 6 phase designs. Optical quality was evaluated by means of Visual Strehl-based-metrics (VS)....

cu(in,ga)se2 thin films (cigs) on metallic substrate (titanium, molybdenum, aluminum, stainless steel) were prepared by a two-step selenization of co-evaporated metallic precursors in se-containing environment under n2 gas flow. structural properties of prepared thin film were studied. to characterize the optical quality and intrinsic defect nature low-temperature photoluminescence, were perfor...

Speckle can seriously degrade image quality in laser-illuminated projection displays. Various solutions appropriate to small microdisplay-based projectors are presented. Illumination optical system and projection optical system design are discussed in order to better understand the critical constraints of size, power consumption, optical efficiency, and performance. DYOPTYKA’s innovative soluti...

Biaxial BaGa4S7 and BaGa4Se7 crystals have been grown by the Bridgman-Stockbarger technique in sufficiently large sizes and with good optical quality to measure the refractive indices and analyze the phase-matching configurations. ©2011 Optical Society of America OCIS codes: (160.4330) Nonlinear optical materials; (190.4410) Nonlinear optics, parametric processes.

we solve the coupled mode equations governing the chalcogenide nonlinear fiber bragg gratings (fbgs) numerically, and obtain the bistability characteristics. the characteristics of the chalcogenide nonlinear fbgs such as: switching threshold intensity, bistability interval, on-off switching ratio are studied. the effects of fbg length and its third order nonlinear refractive index on fbg charac...

This paper gives an overview of current work and research conducted on passive optical networks, namely on dynamic bandwidth allocation and providing quality of service guarantees. The main areas of interest for investigating dynamic bandwidth allocation are grant sizing, grant scheduling and optical network unit queue scheduling. Regarding quality of service parameters bandwidth, delay and jit...

The successful development of an Optical Technology Division quality system for optical radiation measurement services has provided the opportunity to reconsider the existing calibration procedures to improve quality and reduce costs. We have instituted procedures in our calibration programs to eliminate uninformative repetitive measurements by concentrating our efforts on controlling and under...

The hybrid (Optical-Wireless broadband) network with the backbone as optical networks, Passive Optical Networks (PON), and wireless access networks have been proposed to provide good Quality of service (QoS). A Dynamic network solution for adopting both wired and wireless networking methods need to be updated. A Multicast based network coding technique is introduced for improving total network ...

We design high-quality-factor photonic crystal nanobeam cavities formed by two mechanically isolated cantilevers. These "split-beam" cavities have a physical gap at the center, allowing mechanical excitations of one or both of the cavity halves. They are designed by analyzing the optical band structures and mode profiles of waveguides perforated by elliptical holes and rectangular gaps and are ...