A novel scheme is presented that can be used to efficiently pump optical waveguide amplifiers. It is based on the coupling between two adjacent waveguides, where pump light is gradually coupled from a nonabsorbing pump waveguide into the amplifier waveguide. The coupling between the waveguides in such a configuration is calculated using an improved coupled mode theory (CMT). The proposed distri...

In this article some of the different technologies and its functioning as well as some technological aids for people with partial or total auditory deficiency will be presented. The objective of the auditory rehabilitation is to develop the capacity of auditory perception to the individual carrying auditory deficiency, with aid of devices that can amplify the sound. Between these devices, we ci...

A selective and sensitive quartz enhanced photoacoustic spectroscopy (QEPAS) sensor, employing an erbium-doped fiber amplifier (EDFA), and a distributed feedback (DFB) laser operating at 1582 nm was demonstrated for simultaneous detection of ammonia (NH₃) and hydrogen sulfide (H₂S). Two interference-free absorption lines located at 6322.45 cm(-1) and 6328.88 cm(-1) for NH₃ and H₂S detection, re...

We study numerically all-optical slow-light delays in room-temperature single-mode optical fibers induced by stimulated Brillouin scattering. We consider the propagation of a pulse through a cw-pumped Brillouin fiber amplifier, where the carrier frequency of the pulse is tuned near the Stokes resonance. Pulse delay and broadening of the Stokes pulse are studied in the small-signal and gain-satu...

A detailed design of a free electron laser (FEL) amplifier operating in the extreme ultra violet (XUV) and seeded directly by a high harmonic source is presented. The design is part of the 4th generation light source (4GLS) facility proposed for the Daresbury Laboratory in the UK which will offer users a suite of high brightness synchronised sources from THz frequencies into the XUV. The XUV-FE...

A bunch compression scheme designed to obtain high efficiency in relativistic traveling-wave tube (TWT) amplifiers is reported. Bunch compression is achieved by making the bunches stay in more positive slopes of the axial electric field in the amplifier. The resulting momentum gradient across the bunch tends to oppose space-charge spreading and helps to sustain short bunch lengths for long dist...

A novel active feedback frequency compensation scheme is presented in this work. Based on the proposed technique, an amplifier with two main poles in its frequency bandwidth can be easily compensated by introducing a pole-zero pair in a local feedback. The proposed method is mathematically analyzed and then based on the derived formulations, a design procedure is established. The capability of ...

Long BGO (Bi4Ge3O12) and BSO (Bi4Si3O12) crystals coupled with silicon photodiodes have been used to detect minimumionizing particles(MIP). With a low noise amplifier customized for this purpose, the crystals can detect MIPs with an excellent signalto-noise ratio. The nuclear counter effect is also clearly observed and measured. Effect of full and partial wrapping of a reflector around the crys...

was introduced in [2, 3, 6] as a generalization of the coupled quantized harmonic oscillators [7], namely, themodel of light amplifier L−2 1 , and themodel of two-level optical atom L1, whose Hamiltonian model H = K0 +λ(K+ +K−), λ is the coupling parameter. The matrix representations of Lr of least degree satisfying the physical properties K2 =K† 1 († stands for Hermitian conjugation and K0 is ...