Nanoscale Silicon Waveguide Based Thermo-Optic Sensor Using a Compact Mach-Zehnder Interferometer

Abstract

A compact Mach-zehnder interferometer with a novel design of directional couplers and a phase shifter has been presented as a thermo-optical sensor. With the aim of reducing device size to micro and nano dimension silicon-on-insulator technology was employed. That allowed miniaturization of device size through the reduction of its cross sectional area to 0.066 μm 2 and the radius of curvature of both the arms of the directional coupler and S-bends of the phase shifter to 5 μm and C-bends to 3 μm. These nano size device dimensions made it possible to reduce the coupling gap to 0.2 μm, which resulted in a significant reduction in the coupling length. The device geometry and its performance characteristics were analyzed and optimized using coupled mode analysis and finite difference time domain simulation tools, respectively. The wavelength dependent transmission loss of the device was measured at different temperature to verify and validate its performance characteristics. Tested devices showed a remarkable temperature dependent transmission characteristic offering significant changes in transmission loss band -with as low as 0.45 0 C change in substrate temperature. The extinction ratio and the free spectral range of the device were 26 dB and 0.26 nm respectively in the wavelength range of 1549.5 nm -1550.5 nm. These results imply that the devices presented here can be used as compact and highly sensitive thermal sensors and optical switches.

2x4 Hybrid MZI-MMI Configuration with MMI Phase-shifters as a High-speed Optical Switch with Low Power Consumption

“…To minimize heat loss and spreading of heat to reference arm and to other parts, a trench surrounds the modulating arm, similarly to our earlier works (see Refs [19,34,35]). The implementation of this design significantly helps prevent heat spreading and loss by over 90 % as the heat required to drive the switch is directly linked to the device size.…”

Design of a 2 × 4 Hybrid MMI-MZI Configuration with MMI Phase-Shifters

“…To minimize heat loss and spreading of heat to reference arm and to other parts, a trench is created around the modulating arm as described earlier [7,20,21]. The implementation of this design significantly helps prevent heat spreading and minimize loss by over 90% as the heat required to drive the switch is directly linked to the device size.…”

Ferrocene Molecular Architectures Grafted on Si(111): A Theoretical Calculation of the Standard Oxidation Potentials and Electron Transfer Rate Constant

“…Beyond any possible doubt, Silicon is a fundamental material of utmost importance for both applicative purposes and pure science [ 1 ]. In this context, recent research activity shows a growing interest in the area of hybrid, silicon-based, molecular electronics, which is driven by possible technological applications such as biosensors, photovoltaic cells, and optoelectronic devices [ 2 , 3 , 4 , 5 , 6 ]. Different methodologies exist for the preparation of hybrid silicon-based interfaces, relying on the covalent grafting of organic molecules, and these are generally based on ultra-high vacuum (UHV) depositions [ 7 , 8 , 9 ], wet chemistry exploiting UV curing [ 10 , 11 ], electrochemical-based methodologies [ 12 , 13 ].…”