Symmetrical nature of mean of electrical signals during normal operating conditions is used in the fault detection task for dependable, robust, and simple fault detector implementation is presented in this work. Every fourth cycle of the instantaneous current signal, the mean is computed and carried into the next cycle to discover nonlinearities in the signal. A fault detection task is complete...

Optical studies of single molecules in ambient environments, which have led to broad applications, are primarily based on fluorescence detection. Direct detection of optical absorption with single-molecule sensitivity at room temperature is difficult because absorption is not a background-freemeasurement and is often complicated by sample scattering. Here we report ground-state depletionmicrosc...

Ahstruct-An optical orthogonal code is a family of (0,l) sequences with good auto-and cross-correlation properties, i.e., the autocorrelation of each sequence exhibits the " thumbtack " shape and the cross correlation between any two sequences remains low throughout. The study of optical orthogonal codes has been motivated by an application in a code-division multiple-access fiber optic channel...

In an access network based on a passive optical network architecture, coherent detection is attractive since it allows for high receiver sensitivity coupled with inherent frequency selectivity. Nevertheless, solutions employed in core networks are prohibitively complex and costly, requiring the optical complexity of the coherent receivers to be reduced to make them feasible for access networks....

We describe a collective-state atomic interferometer (COSAIN) with the signal fringe as a function of phase difference or rotation narrowed by √ N compared to a conventional interferometer, N being the number of atoms, without entanglement. This effect arises from the interferences among collective states, and is a manifestation of interference at a Compton frequency of 10× 1030 Hz, or a de Bro...

Adaptive optical-coherence-domain reflectometry (OCDR) is performed by use of an adaptive interferometer and homodyne detection. The adaptive element of the interferometer is a photorefractive quantum-well device in a two-wave mixing geometry. The mixing self-adaptively maintains constant relative phase between the signal and reference waves and dynamically compensates gross movements of the sa...

This article reviews the recent progress in optical biosensors that use the label-free detection protocol, in which biomolecules are unlabeled or unmodified, and are detected in their natural forms. In particular, it will focus on the optical biosensors that utilize the refractive index change as the sensing transduction signal. Various optical label-free biosensing platforms will be introduced...

Semiconductor laser amplifiers have been subject of great interest for several years now. Travelling wave semiconductor laser amplifiers have recently been implemented in optical fibre communication systems as optical repeaters and optical preamplifiers. Automatic gain control (AGC) of laser amplifiers is required in more reliable optical communication systems to compensate for the effect relat...

Based on the physical phenomena of optical effects produced by the partial discharge (PD) and on the characteristics of fluorescent fiber sensing of weak fluorescent signals, a PD measurement system using a fluorescent fiber sensor was designed. The main parameters of the sensing system were calculated, an experimental testing platform for PD simulation in the lab was established, and PD signal...