Tunable Integrated Photonic Devices

Abstract

This work is based on the study of the thermo-optic e ect and the physics behind it. The software used to do the simulations of the designs is FIMMWAVE, it is a product of Photon Design. The general goal is to observe the impact of the thermo-optic e ect on different structures. The main idea is to locate heaters on di erent structures, where a voltage is applied. Therefore, the heaters get a higher temperature and with that also the structure. The impact of this temperature increase is a variation of the refractive index. It is done analyzing some parameters as the heater material, the metal dimensions, the distance between the heater and the waveguide, the maximum current or the losses. The studied structures are a phase shifter and multimode interferometer devices (MMI). For each of them, the basic structure is analyzed and then some device modi cations are introduced. Two types of phase shifters are analyzed, one with a heater on the top and one with heaters on the side. The multimode interferometer devices are an adjustable power attenuator and a variety of adjustable power splitters. The adjustable power attenuator consists of three areas: a 3dB coupler, a phase shifter and a power combiner. All three are explained in detail as well as the relation of the transmission parameter with respect to the power applied and the length of the waveguide are shown. The analysis of the adjustable power splitter is divided into three cases: 1x2x2, 2x2 and 2x4x2 adjustable power splitters. All the cases are analyzed in detail and compared.