ALL-OPTICAL KARHUNEN-LOEVE TRANSFORM USING MMI COUPLERS FOR IMAGE PROCESSING APPLICATIONS

Abstract

In this study, we present a method for all-optical image compression using all-optical Karhunen-Loeve transform (KLT). The KLT was designed in all-optical domain using only one multimode interference (MMI) coupler. The Karhunen-Loeve transform (KLT) is very attractive for image processing applicaons due to its computing efficiency, residual correlation, and rate distortion criteria benefits. The restricted multimode interference coupler with suitable locations of input and output ports was used to realize the KLT. The numerical simulations were applied to design and analyze the new hardware architecture of the KLT. The image compression has succesfully realized on the all-optical KLT within the RGB visible wavelength with high fabrication tolerance ± 2µm in the MMI length. The signal procesisng is performed in all-optical domain and can be integrated into a single chip within an AI camera. The proposed method can process image signals directly in optical domain, so it can improve signal processing speed and reduce the energy consumption.