Modeling and experimental investigation of an integrated optical microheater in silicon-on-insulator

Abstract

A linear piecewise model has been formulated to analyze the performance of a metallic microheater integrated with single-mode waveguides (λ∼1550 nm) in silicon-on-insulator (SOI). The model has been used to evaluate integrated optical microheaters fabricated in a SOI substrate with 2 µm device layer thickness. The Fabry-Perot modulation technique has been used to extract the effective thermo-optic phase shift and response time. The effective thermal power budget of P_eff,π∼500 µW (out of actually consumed power P_π=1.1 mW) for a π phase shift and a switching time of τ∼9 µs, have been recorded for a typical Ti heater stripe of length L_H=50 µm, width W_H=2 µm, and thickness t_H∼150 nm, integrated with a Fabry-Perot waveguide cavity of length ∼20 mm. It has been shown that the performance of a heater improves (in terms of power budget) as the length of a microheater decreases. However, smaller heater size requires higher joule heating to obtain a desired phase shift, which is again found to be dependent on polarization of the guided mode because of thermal stress.

Hybrid Graphene-Silicon Based Polarization-Insensitive Electro-Absorption Modulator with High-Modulation Efficiency and Ultra-Broad Bandwidth

“…Other waveguide structures could also be applied onto this platform, e.g., slot photonic crystal waveguide [12]. Moreover, by means of the large thermo-optic coefficient of silicon [13], the thermal modulation method has also been explored for silicon modulators, but the modulation speed was limited and the energy consumption was relatively high. Therefore, new hybrid silicon modulators with better performance and smaller size are highly desirable to fulfill the modulation requirements of high capacity on-chip optical interconnects [14].…”