# Design of Mach-Zehnder Interferometers

AbstractIn this paper, it will be described the design, fabrication and data analysis of a Mach-Zehnder Interferometer for a silicon-on-insulator fabrication. Simulated results will be obtained by using the Lumerical software and they will be compared with the experimental one to verify the specification of the project and to analyze the variability of the manufacturing process.

# Introduction

The EDX’s course “Silicon Photonics design, Fabrication and Data Analysis”, taught by Mr. Lukas Chrostowski from UBC, is an online course which gives the basic knowledge of all the necessary steps to manufacture a silicon photonic device. The interest in this matter born from its importance in IT technology. In fact, silicon photonic devices permit to move information faster and farther respect other technologies, reducing the cost and increasing the performances.

The objective of this course project is to develop a Mach-Zehnder Interferometer in order to understand how silicon photonic devices operate and how to design and analyze the data of them.

# Theory

The Mach-Zehnder Interferometer (MZI) is a device which, having as an input a light source, it splits it in two parts and it recombines them to analyze if a constructive/destructive interference occurs.
The MZI is mainly done by using two 50-50 splitters (one operating as a splitter and one as a combiner) and two optical waveguide paths.

To achive the split of light, we can use a Y-Branch: it takes as imput the light source (described by the intensity $$I_i$$ and the electric field $$E_i$$) and it split it in two portions having intensity $$I_{1,2}=I_i$$/2 and electric field $$E_{1,2}=E_i$$/$$\sqrt{2}$$