The use of wide-field multi-object fiber-input spectrographs for large redshift surveys introduces the possibility of variations in the observed signal-to-noise ratio across the survey area due to errors in positioning the fibers with respect to the target image positions, leading to position-dependent errors in the survey catalog. This paper brings together a comprehensive description of the s...

The classic analysis by Anderson and Malone (Biophys J 14: 957-982, 1974) of the osmotic flow across membranes with long circular cylindrical pores is extended to a fiber matrix layer wherein the confining boundaries are the fibers themselves. The equivalent of the well-known result for the reflection coefficient sigma0 = (1 - phi)2, where phi is the partition coefficient, is derived for a peri...

ABSTRACT. A novel and accurate refractive index profile synthesis method for optical fibres is developed using knowledge of the fundamental or higher order mode near field. This fundamental method is based on inverse transmission line principles. From Maxwell’s equations, we derive a transmission line equivalent circuit for a circularly symmetric optical fibre with arbitrary refractive index. W...

We study novel designs of hollow-core antiresonant fibers comprising multiple materials in their core-boundary membrane. We show that these types of fibers still satisfy an antiresonance condition and compare their properties to those of an ideal single-material fiber with an equivalent thickness and refractive index. As a practical consequence of this concept, we discuss the first realization ...

one of the most effective ways to reach yield stability with low input is increasing diversity through utilizing intercrops in agro-ecosystems. a field experiment based on a randomized complete block design with six treatments and three replications and two crops, green pea and nutrifed millet, was carried out at research farm of agriculture and natural resources of kerman during growing season...

We demonstrate a photon-counting optical time-domain reflectometry with 42.19 dB dynamic range using an ultra-low noise up-conversion single photon detector. By employing the long-wave pump technique and a volume Bragg grating, we achieve a noise equivalent power of -139.7 dBm/√Hz for our detector. We perform the OTDR experiments using a fiber of length approximate 217 km, and show that our sys...

We report significant performance improvement of a mode-locked fiber laser gyroscope. A Fabry-Perot cavity GaAlAs laser diode whose front facet was antireflection coated was used as a gain medium. The rms noise equivalent rotation rate measured with a time-interval counter was improved to 0.06deg/ radicalh. The long-term drift of the gyroscope signal was reduced to 100deg/ radicalh after a pola...

An existing industrial sensor is used to monitor the production of synthetic polymer fiber, by measuring changes as fiber passes through an electromagnetic field. Dedicated analog circuitry performs low-level processing to detect specific physical structures in the fiber. Measurement of a given fiber requires fine-tuning of the analog circuitry, so the sensor cannot be configured to optimally m...