Quantum cascade lasers (QCLs) have become important laser sources for accessing the mid-infrared (mid-IR) spectral range, achieving watt-level continuous wave operation in a compact package at room temperature. However, up to now, wavelength tuning, which is desirable for most applications, has relied on external cavity feedback or exhibited a limited monolithic tuning range. Here we demonstrat...

semiconducting carbon nanofibers (cnf) are prepared from three different sources, i.e., acetylene, ethanol, and cotton by the chemical vapor deposition (cvd) process. these fibers are having rich elastic, engineering and conductivity properties. fresh self-compacting concrete (scc) flows into place and around obstructions under its own weight to fill the formwork completely and self-compact, wi...

A compact and sharp rejection UWB microstrip bandpass filter is developed using left handed metamaterials. For realizing a backward-wave propagation medium, two split ring resonator (CSRR) in the back substrate side and also one series capacitor etched in the host line, are used to produce a negative effective ε and μ, simultaneously. Moreover, in the proposed structure, two doublets parallel c...

Information revolution implies that multimedia networks need high bandwidth real-time communication services. At present, optical fibre is the only transmission medium offering such large bandwidth with low loss communication links. To amplify an optical signal with a conventional repeater, one performs photon to electron conversion, electrical amplification, retiming, pulse shaping, and then e...

A slow-light medium based on multiple, closely spaced gain lines is studied. The spacings and relative strengths of the gain lines are optimized by using the criteria of gain penalty and eye-opening penalty to maximize the fractional delay defined in terms of the best decision time for random pulse trains. Both numerical calculations and experiments show that an optimal design of a triple-gain-...

Cold interstellar gas systems have been used to constrain dark matter (DM) models by the condition that heating rate from DM must be lower than astrophysical cooling of gas. Following methodology Wadekar and Farrar (2021), we use medium a gas-rich dwarf galaxy, Leo T, Milky Way-environment cloud, G33.4-8.0 DM. T is particularly strong system as its can lowest among all objects in late Universe ...