Microstructured optical fibre with tunable birefringence

An approach is presented for manipulating and tuning birefringence in a microstructured photonic crystal optical fibre. This is accomplished by filling certain airholes with an index tunable polymer which creates a tunable asymmetry in the index profile of the cladding. It is also demonstrated that fibre waveguides with three- and sixfold symmetry exhibit minimal birefringence     

Polarisation tuning by micro-fluidic motion in air-silicamicrostructured optical fibre

The ability to manipulate the polarisation of light in an optical fibre by moving fluids within air channels that run along the length of the fibre-cladding region is demonstrated. A polarisation tuning of 2π phase change is achieved in a 4 cm length of fibre. The displacement of fluid in the channels measured against temperature is in good agreement with the theoretical predictions     

Novel waveguide structures for enhanced fiber grating devices

An emerging class of fiber waveguide structures is being used to increase the functionality of fiber gratings, enabling new devices critical to the performance of next generation light-wave communications systems. These devices rely on advances in the fabrication of optical fiber waveguides, which go beyond the conventional doped silica design and fall into two general categories: 1) local modifications to the waveguide after fabrication and 2) fibers drawn with modified claddings that include nonsilica regions throughout their length. This paper provides a comprehensive review of emerging fiber waveguide structures that enhance the functionality of optical fiber grating devices. Two examples of technologies that fall into the first category are thin metal films deposited onto the cladding surface, which can be used for thermal tuning and infusion of nonsilica materials into the air regions, which change the waveguide structure and can provide enhanced tunability. The second category is typified by air-silica microstructured optical fibers, which contain air-voids that run along the length of the fiber. These fibers have unique cladding mode properties that can be exploited in fiber grating based devices     

Influence of scattering on transmission through long-period fiber gratings and tunable microstructure fibers

Controlled optical scattering within or around an optical fiber provides a potentially useful mean for adjusting its transmission characteristic. This approach can complement conventional methods based on the establishment of well-defined variations in the index of refraction of the core or the cladding of the fiber. We describe the use of a highly scattering submonolayer of nanoparticles deposited onto the fiber surface for adjusting the resonance wavelength, depth, and width of an in-fiber long-period grating filter. We also introduce a polymer-dispersed liquid-crystal material that has a thermally tunable scattering cross section and can be incorporated into the channels of a microstructure optical fiber; this system may provide the means for a fiber-based scattering switch.