Fig. 1. Methods to improve computing power and energy efficiency ratio in the “post-Moore era” (FinFET is field effect transistor, EUV is extreme ultraviolet lithography, GAA is gate-all-around FET, UCIe is universal chiplet interconnect express, and chiplet is an integrated circuit block)

Fig. 2. Overview of development model and main technologies of optical computing

Fig. 3. Representative achievements of early digital optical computing technologies

Fig. 4. Fundamental building blocks and releated technical solutions of major optical computing based on photonic integrated circuits (PICs). (a) Main technical schemes of analog optical computing for PICs; (b) basic building blocks required for optical computing based on PICs; (c) main technical schemes of digital optical computing for PICs

Fig. 5. Major advances in free-space analog optical computing. (a) Image filtering and convolution operations are achieved by modulating point spread function (PSF); (b) operations such as optical differentiation/integration and VM-MAC are achieved by modulating MTF (modulation transfer function) of the system on the spectral plane; (c) modulate parameters of each pixel in each diffractive or scattered layer to realize optical interconnection and optical transformation

Fig. 6. Optical matrix convolution computing system based on multi-imaging-casting architecture^[138]