Light Propagation in Non-Hermitian Optical Structures

This thesis incorporates the concept of light propagation in non-Hermitian media. We use the waveguide arrays and one dimensional photonic crystals as the frameworks for our investigations. The notion of non-Hermiticity is implemented into these structures by considering the fact that the electromagnetic parameters of an optical medium can contain imaginary components. These imaginary components are responsible for the field amplification and attenuation. Our studies open new possibilities to observe intriguing phenomena ranging from profound quantum mechanical concepts like bound states in the continuum and Anderson localization to more application-oriented features like lasing and absorbing instabilities.