Uncovering a third function of the transistor beyond switching and amplification: coupled photo-responsive oscillators for in-sensor computing

Abstract

To enable in-sensor computing that emulates the biological brain's ability to process visual information with minimal energy consumption, we demonstrated brain-inspired coupled twin photo-responsive oscillators (CT-PROs) that integrate sensing and signal processing within a single device. The CT-PROs utilize a single-transistor latch (STL) phenomenon to generate iterative oscillations modulated by incident light. Each PRO, structurally identical to a metal–oxide-semiconductor field-effect transistor (MOSFET), is capable of sensing optical stimuli and producing corresponding oscillatory outputs governed by the STL mechanism. Notably, the PRO obviates the need for an external photodetector because it inherently operates as both an oscillator and a photodetector, functioning as a Janus-like device. The oscillation characteristics vary with input light intensity and wavelength, enabling detection of both parameters by observing whether synchronization or desynchronization occurs between the CT-PROs under different illumination conditions. The CT-PROs can be used for a coupled oscillator network (CON) with in-sensor computing capabilities. As an application of the PRO-based CON, edge detection was conducted. Then, edge maps generated by the proposed CON were used to aid in classification. These results highlight the potential of PRO-based CONs for in-sensor vision systems.