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.