Micro-perforated absorber is a newly developed sound absorber, and it has a number of attractive features: • Unlike conventional perforated absorbers, micro-perforated absorber can be made from transparent materials like plastic glass. • Unlike commonly used fibrous absorptive materials, micro-perforated absorber is fibrous-free and thus, there is no health concern. • Micro-perforated membranes...

We describe two different, double-sided interferometer designs for measuring material stability. Both designs are balanced interferometers where the only optical path difference is the sample and the reference beams are located within the interferometer. One interferometer is a double-pass design, whereas the other is a single-pass system. Based on a tolerancing analysis, the single-pass system...

PURPOSE We investigated the correlations between optical quality parameters obtained from the double-pass system and ocular aberrations obtained from the ray-tracing aberrometer in multifocal intraocular lens (IOL) implanted eyes. MATERIALS AND METHODS Twenty eyes from 20 patients were enrolled in this study. Modulation transfer function cutoff frequency, The Strehl ratio, objective scatter i...

We compare two methods for measuring the modulation transfer function (MTF) of the human eye: an interferometric method similar to that of Campbell and Green [J. Physiol. (London) 181, 576 (1965)] and a double-pass procedure similar to that of Santamaria et al. [J. Opt. Soc. Am. A 4, 1109 (1987)]. We implemented various improvements in both techniques to reduce error in the estimates of the MTF...

Device modeling and simulation studies of a Cu(In1-x,Gax)Se2 (CIGS) thin film solar cell have been carried out. A variety of graded band-gap structures, including space charge region (SCR) grading, back surface region grading, and double grading of the CIGS absorber layer, are examined. The device physics and performance parameters for different band-gap profiles were analyzed. Based on the sim...

The double-pass erbium-doped zirconia fiber amplifier (EDZFA) is proposed and demonstrated to provide a wide-band amplification as well as flat-gain operation in both the Cand L-band regions using only a single-gain medium. The proposed amplifier utilizes an erbium-doped zirconia fiber (EDZF) with erbium ion concentration of 2800 ppm as a gain medium. The medium is fabricated in a ternary glass...

In this paper, the periodic double-layer graphene ribbon arrays placed near a metallic ground plate coated by a dielectric layer are proposed and analyzed by the coupled-mode theory (CMT) to predict the perfect absorption response in the mid-infrared region. Numerical simulations of the finite-difference time-domain (FDTD) method confirm this effect and give the underlying physical origin. The ...