On-chip All-optical Haar Transform based on a 4x4 MMI coupler cascaded with a 2x2 MMI coupler for Image Compression

We present a new method for image compression in all-optical domain. The new hardware architecture is suitable for directly integrating with digital cameras for image processing. The proposed architecture is based on the optical Haar wavelet transform (HWT) using only one 4x4 multimode interference (MMI) coupler cascaded with a 2x2 MMI coupler. The processing of images therefore is at very high speed.