Artificial neural networks find applications in electronics, informatics, medical purposes and many more nowadays. As the computational demand increases, a well know drawback of classic electronics is its high power consumption. In the last few years many solutions have been proposed to overcome this problem, one of the most promising being a hybrid design which uses a silicon photonic circuit as weight matrix block. The use of photonics is encouraging thanks to its low power consumption and high speed. In this work I focused on a 3x3 silicon photonic circuit made of Mach-Zehnder interferometers. It was originally designed as optical fiber switch and later adapted to neuromorphic computing by a Dutch research group.