Abstract
In this paper, we present a continuous-wave tunable fibre ring laser operating in the L-band. A bi-directional pumped L-band erbium-doped fibre amplifier provides gain to the loop. Tunability is achieved by bending a single-mode fibre taper using a micrometer drive, controlling in this way the spectral cavity losses. Laser emission is achieved between 1587 and 1606 nm, and low variation of the output laser power is observed over all the tuning range.

Abstract
A new scheme based on four-wave mixing is presented using a ring erbium-doped fibre laser and tuneable fibre Bragg gratings that can effectively perform wavelength conversion in a wide wavelength range. An application of this wavelength-conversion architecture to optical communications is also presented.

Abstract
Two different architectures of multiplexers/demultiplexers based on 4 x 1 and 1 x 4 configurations are discussed. These architectures are implemented using apodized fibre Bragg gratings as optical filters and optical circulators. The spectral characteristics of the devices for channel separations of 100 GHz and 50 GHz are analysed and their performance is evaluated. Optical switch and cross-connect configurations are also demonstrated.

Abstract
Definition of channel waveguides on hybrid sol-gel material was demonstrated using a 248 nm UV excimer laser. without mixing organic photoinitiators in the solution preparation step. Thin films fabricated by hydrolysis and polycondensation of methacryloxypropyltrimethoxysilane (MAPTMS) doped with zirconium oxide were deposited by spin-coating on soda-lime glass substrates (n=1.514). Channel waveguides were defined by microlithography and then covered by a protective layer composed of a combination of MAPTMS and tetramethoxysilane (TMOS). Finally, after cutting and polishing, the waveguides were optically characterised.

Abstract
The main objective of this work is to investigate the correlation between meditation stages and the hypnagogic stages of sleep and awakening. It reports the study on the brain electric activity during Yôga Svásthya meditation stages. These data were obtained by means of scalp electroencephalograms (EEGs), and confronted with the stages of meditation and hypnagogic EEG stages. The latter were based on established criteria through the study of the duration of individual occurrences of each of the nine considered hypnagogic EEG stages. Analysis made concerns time, frequency, power and signal amplitude. The results show that meditation stages reach only the first two hypnagogic EEG stages, and the spectral analysis of the EEG confirmed a dominance of rapid rhythms (beta) while the presence of lower ones (delta and theta) are not significant.

Abstract
We describe a new regime of operation where sub-10-fs ultrashort laser pulses with symmetric spectra centered at 800 nm can be directly generated from a prism-dispersion-controlled modelocked Ti:sapphire oscillator that only uses commercially available standard optics.