A study on the novel thermo-optic digital optical switch integrated with variable optical attenuators

Abstract

This Thesis presents a novel digital thermo-optic switch based on polymer waveguide. The proposed switch consists of a conventional $1\times2$ digital optical switch and compact variable optical attenuators and both elements are integrated in series The operation principles of the new switch are adiabatic mode evolution, total internal reflection, and higher-order mode filtering of light. The mode propagation theory based on beam propagation method(BPM) is used in the analysis of the new switch structure. The polymer waveguide is fabricated by the reactive ion etching (RIE)method. The fabricated switches show very low crosstalk values less than -40dB even with the low switching power of about 170mW at 1.55$\mu$m.