On-chip CMOS-compatible all-optical integrator

TLDR

Photonic devices promise speeds far exceeding electronics, yet integrating them remains challenging, and few fundamental building blocks exist for all‑optical circuits that could overcome electronic speed limits. The study reports the first monolithic all‑optical temporal integrator on a CMOS‑compatible platform. The authors construct a CMOS‑compatible monolithic optical waveform integrator using a passive micro‑ring resonator. The device, a lightwave capacitor‑like element, performs time integration of arbitrary optical waveforms with picosecond resolution (~200 GHz) and a hold time near a nanosecond, positioning it as a building block for ultrafast data‑processing, optical memories, and real‑time differential‑equation computing. Ferrera et al.

Abstract

One reason for using photonic devices is their speed—much faster than electronic circuits—but there are many challenges in integrating the two technologies. Ferreraet al. construct a CMOS-compatible monolithic optical waveform integrator, a key building block for photonic circuits. All-optical circuits for computing and information processing could overcome the speed limitations intrinsic to electronics. However, in photonics, very few fundamental 'building blocks' equivalent to those used in multi-functional electronic circuits exist. In this study, we report the first all-optical temporal integrator in a monolithic, integrated platform. Our device—a lightwave 'capacitor-like' element based on a passive micro-ring resonator—performs the time integral of the complex field of an arbitrary optical waveform with a time resolution of a few picoseconds, corresponding to a processing speed of ∼200 GHz, and a 'hold' time approaching a nanosecond. This device, compatible with electronic technology (complementary metal-oxide semiconductor), will be one of the building blocks of next-generation ultrafast data-processing technology, enabling optical memories and real-time differential equation computing units.