Microstructured fibers

Optical fibers build a key element in our modern information society. Conventional fibers guide light through total internal reflection. Such fibers are easy to fabricate and yield sufficiently low loss for most applications. However, they provide limited tuning capabilities, since the only degrees of freedom are the material decomposition and the core radius, and they require core materials with a higher refractive index than in the surrounding in order to enable total internal reflection.

Microstructured fibers allow to circumvent these drawbacks of conventional fibers. However, they support leaky modes that radiate part of the light perpendicularly away from the fiber core. Hence, conventional theoretical descriptions of light propagation break down. We develop rigorous theories for the linear and nonlinear propagation of leaky modes and investigate the resulting differences to the propagation of bound modes and their potential for applications.