Silisyum tabanlı dielektrikler: Tümleşik optikte kullanıma yönelik büyütme ve inceleme

In recent years, growing attention has been paid to silicon based dielectrics, suchas silicon oxynitrides, silicon nitrides, and semiconductor doped silicon oxides, allcombined under the name silica on silicon technology. This attention has beenmotivated mainly due to their excellent optical properties such as well controlledrefractive index and high transparency over a wide range of wavelength.In accordance with the main goal of this study that relied on the utilization ofsilicon based dielectrics and their optimization for applications in integrated op-tics, an emphasis was given to optimize the compositional and optical propertiesof these materials. A detailed quantitative compositional analysis using Fouriertransform infrared spectroscopy resulted in identification of the germanosilicatedielectrics as the most promising candidates for use in integrated optics. Thefirst reported systematic study of propagation losses for different-index planarwaveguides by using prism coupling method was correlated with the composi-tional analysis. This study had an important outcome for planar waveguidesfabricated with germanosilicate core layers resulting in the lowest propagationloss values reported so far for as deposited CVD-grown films at λ=1.55 µm, elim-inating the need for costly and cumbersome annealing process.An improvement of the prism coupling technique led to a new approach forelasto-optic characterization of thin polymer films. This completely new methodallows one to determine the optical anisotropy and out-of-plane mechanical prop-erties and to correlate both in order to obtain the elasto-optical properties of thinpolymer films, for the first time.Of interest as potential electro-optic material, we have concentrated on ther-mally poled germanosilicate films deposited on fused-silica substrates by PECVD.ivvAs a result of an optimization study, we demonstrated a record peak nonlinearcoefficient of ∼1.6 pm/V, approximately twice as strong as the highest reliablevalue reported in a thermally poled fused silica glass.Finally, we have demonstrated several applications of this technology in thefield of integrated optics. Since optical waveguides constitute the building blocksof many integrated optical devices, we had first concentrated on design and opti-mization of waveguides employing germanosilicates as the core layers. The finalstep of our work concentrated on design and implementation of microring res-onator devices based on germanosilicate layers.Keywords: Integrated optics, Silicon dielectrics, Silicon oxide, Silicon oxynitride,Germanium, Germanosilicate, PECVD, FTIR, Waveguide, Optical absorption,Prism coupling, Elastic modulus, Elasto-optic coefficient, Birefringence, Nonlin-earity, Electro-optic coefficient, Thermal poling, Ring resonator.