all-optical symmetric cosine and sine transforms using multimode interference structures
A variety of unitary transforms have attracted considerable attention for their application in data, image compression and other signal processing applications. Among many transforms, the Karhunen-Loeve transform (KLT) is known to be optimal because of its advantages of computational efficiency, residual correlation and rate distortion criterion. In this paper, it is shown that the all-optical modified symmetric cosine transform (SCT) and symmetric sine transform (SST) that are related to the KLT can be realized using multimode interference structures on silicon wire waveguides. The transfer matrix method (TMM) and the beam propagation method (BPM) are used to verify and optimally design the proposed devices.
karhunen-loeve transform symmetric cosine transform symmetric sine transform beam propagation method multimode interference coupler silicon on insulator data compression image processing all-optical signal processing