Erik Knudsen

High-birefringent photonic crystal fiber

A highly birefringent photonic crystal fiber design is analysed. Birefringence up to 10/sup -3/ is found. Random fluctuations in the cladding design are analysed, and the fiber is found to be a feasible polarization maintaining fiber.

Photonic crystal fibers; fundamental properties and applications within sensors

Since the first experimental demonstration of a photonic crystal fiber (PCF) in 1996 by Knight et al. the optical properties and the fabrication of such fibers have attracted significant attention. The fiber structure with a lattice of air holes running along the length of the fiber provides a large variety of novel optical properties and improvements compared to standard optical fibers. The stack-and-pull procedure used to manufacture PCFs is a highly flexible method offering a large degree of freedom in the fabrication of PCFs with specific characteristics. A few of the remarkable optical properties of silica based PCFs are described and their applications within sensors are summarized.

Macro-bending loss estimation for air-guiding photonic crystal fibres

Optical fibres operating by the photonic bandgap effect offers an alternative approach to evanescent field waveguides for opticai sensing applications. In addition to this, these photonic crystal fibres provide completely new waveguiding properties, which include different macro-bending loss performance compared to standard optical fibres. A first estimation of these new properties is demonstrated for air-guiding fibre designs by combining accurate vectorial mode analysis and an adaptation of more traditional macro-bending loss theory.