I. Introduction
Programmable optical processors are promising structures for ultrafast and energy efficient computation in classic and quantum photonics. These processors efficiently perform the vector-matrix multiplication extensively used in artificial intelligence and machine learning tasks. Due to the inherent parallelism presents in optics in contrast with sequential operations in electronics, optical processors are faster offering better energy efficiency compared to their electronic counterparts [1]. Today, deep learning is facing growing computational demand limiting its development if we continue using conventional electronic processors [2]. Energy efficient computational accelerators fabricated in silicon photonic (SiPh) are candidates to meet the computational demands of future machine learning and deep learning tasks.