Nanostructuring of dielectric materials for applications in photonics

Dielectric photonic crystals enable the manipulation of the direction of propagation of light. Due to the broad spectral transparency of dielectrics, such structures are of particular interest in the fields of optics and photonics. Periodic structures - periodic changes of the refractive index - can be implemented in multiple spatial directions, so that they can be implemented as simple 1D-systems such as a DBR mirror up to complex 3D-systems. The effort of producing such structures increases with the number of dimensions. Conventionally, these structures are created using electron and ion beam lithography. These methods produce strong charging effects of the dielectric. This problem generally leads to considerable additional efford, which also leads to significantly longer process times. In this work, the focus is on a novel method that uses temporally shaped femtosecond laser pulses. This method can be used to avoid this problem. The novel manufacturing method is compared in this work with the conventional methods. The design of a "fano filter" is implemented as a comparison structure. Different depth profiles of the structures with diameters in the range 400 nm to 1200 nm at a depth of up to more than 8 μm are realized, resulting in aspect ratios of up to 17. The resulting deep channels in the substrate have an average diameter of less than 300 nm. The characterization of these structures is mainly carried out by cross-sectional analysis by means of focused ion beam technology and a polarization-selective InP filter is spectrally analyzed.