Abstract
High strength, first order Bragg Grating Waveguides are inscribed in the core and cladding of optical fibers using oil immersion femtosecond direct laser-writing. A laser-induced birefringence of 2.05x10(-4) was inferred from polarization split Bragg resonances.

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
Phase-shifted Bragg Grating Waveguide filters were formed in bulk glass for the first time by femtosecond laser direct writing. A narrow, tunable 0.1-nm transmission window at 1550-nm is demonstrated for tunable p and other phase-shifts. © 2009 Optical Society of America.

Abstract
Fiber Bragg gratings (FBGs) are today fundamental components in fiber optics. They can be used as sensors, in signal processing, e.g. telecom applications, as wavelength stabilizers in fiber lasers or in dispersion compensators. However, there are applications where the demand for fiber Bragg gratings is not compatible with standard photosensitivity techniques like germanium doping or hydrogen loading. Examples are their use as laser-mirrors in spliceless all fiber fiber-laser solutions or the fiber Bragg grating inscription in suspended core all silica fibers for evanescent field sensing. Fiber Bragg grating inscription with femtosecond-laser exposure is a challenging new method to realize grating structures for waveguides made of materials which do not provide UV-photosensitivity. Especially fs-IR-inscription has been demonstrated for Bragg grating inscription in a variety of material systems such as boron-silica glass, sapphire and pure silica glass. The feasibility of the phase mask FBG inscription technique with DUV femtosecond lasers was also shown, which allows grating inscription even in pure silica microstructured fibers. The phase mask inscription method requires that the fiber will be placed directly behind the phase mask. While the laser beam should be focused onto the fiber to support nonlinear material interaction, this inscription method also leads to phase mask degradations, presumably due to non-bridging oxygen holes (NBOH). Our solution to avoid the mask degradation is to increase the space between fiber and phase mask by using a Talbot-interferometer. Another advantage is the wavelength versatility of this inscription setup. Due to the short temporal coherence length of the femtosecond pulses, the angular alignment variability of the interferometer mirrors is limited and restrictions concerning the wavelength versatility of the interferometer arise. Grating arrays in pure silica suspended core fibers are demonstrated as an example for the versatility of the inscription arrangement. © 2009 SPIE.

Abstract
The refractive index distribution and birefringence of electron-beam directly-written waveguides in flame-hydrolysis silica have been characterized by means of micro-reflectivity and mode characterization. These results allow the detail design and fabrication of complex optical devices using this fabrication technique. © 2003 Optical Society of America.

Abstract
The fabrication and characterisation of Long Period Gratings in fibre tapers is presented alongside supporting theory. The devices possess a high sensitivity to the index of aqueous solutions due to an observed spectral bifurcation effect.