Introduction: Two-photon absorption (TPA) has recently received attention with optical performance monitoring of group velocity dispersion, polarisation mode dispersion and optical signal-to-noise ratio having been demonstrated [1, 2]. TPA is a weak, nonlinear process and as such is inefficient. A number of different detectors have previously been used to overcome the low level of TPA in semico...

In this paper, a vector channel madel is pposed and some statistical pmperties of the asymptotic efficiency of the decorrelating detector with base-station awys are investigated. It is shown that we can get gain over the conventional deamlator by employing antenna arrays and the gain i n " s as the number of antennas inneases and the angle dispersion It is also shown that we can increase the as...

This work first reports the preparation of super-amphiphilic silica-nanogel composites to reduce the contact angle of water to increase the diffusion of pollutant into adsorbents. In this respect, the silica nanoparticles were encapsulated into nanogels based on ionic and nonionic polyacrylamides by dispersion polymerization technique. The morphologies and the dispersion stability of nanogel co...

The use of Cepheids as distance indicators on Galactic and extragalactic distance scales is based upon the Cepheid period luminosity (PL) and period luminosity colour (PLC) relations. These relations are usually derived in terms of the properties of Cepheids at mean light – i.e. averaged over their pulsation cycle. In this paper, we derive a physical argument for the existence of PL and PLC rel...

We propose a transmission-based dispersion compensator employing an apodized, unchirped fiber Bragg grating (FBG). A theoretical model for dispersion compensation in transmission based on the dispersive properties of the periodic structure is developed. A figure of merit is defined for optimization of the grating parameters for maximum recompression of dispersion-broadened optical pulses in lon...

-. The beam-beam interaction with a crossing angle and with a compensating crab angle is simulated and treated partially analytically. The crab angle is obtained by transversely deflecting cavities in one case and by a dispersion in the accelerating cavities in another case. Resonances which are excited by the action of the crab cavities are investigated. Tolerances for the cavity voltage and f...