Simulation of dynamical refractive index change in on-chip optical devices

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Bilimleri Enstitüsü, Türkiye

Tezin Onay Tarihi: 2019

Tezin Dili: İngilizce

Öğrenci: ANIL ASLAN

Danışman: Serdar Kocaman

Özet:

Theoretical modeling and numerical verification are essential in integrated photonics for designing optimized structures as well as interpretation of the experimental results. In this thesis, a dynamically changing refractive index modification for the Finite Difference Time Domain (FDTD) method is proposed, implemented with C++ and results are compared with recent experimental studies. The proposed method is based on the idea of the time-domain simulation of the non-stationary objects while satisfying the conventional Yee algorithm. As a case study with the proposed modified method, optical analog of the electromagnetically induced transparency (EIT) phenomena in coupled on-chip cavities such as double microring resonators and L3 coupled-cavity photonic crystals is numerically analyzed in detail. Light trapping coming from EIT is an important topic for future photonic integrated circuits and systems observing EIT with micro-cavities are quite suitable for testing dynamical refractive index change. The simulation results with the proposed method are initially verified with an open electromagnetic wave simulator, MEEP, for the constant refractive index cases through the comparison of the transmission spectra. Then, experimental studies are numerically investigated with the proposed modified FDTD method and the calculated delay (light storage) values are consistent with the measurement results proving the usefulness of the developed method.