Enables storage, delay, and control of light within a single photonic chip

A joint research team from Seoul National University and the University of Seoul has developed a programmable photonic integrated circuit that can slow light on demand, a capability expected to have applications in low-power optical computing for AI servers and next-generation optical communication systems.

The team, led by professors Namkyoo Park and Sunkyu Yu of SNU’s Department of Electrical and Computer Engineering alongside Professor Xianji Piao of the University of Seoul, built a chip that treats the bright and dark modes of coupled-resonator-induced transparency (CRIT) systems as a single, unified degree of freedom, controlled through two tunable loop couplers.

That design lets the chip reconfigure its delay, bandwidth, and frequency conversion properties after fabrication — a significant departure from conventional photonic devices, whose light-slowing properties are fixed once manufactured.

“Being able to reprogram how a chip controls light, rather than redesigning the hardware each time, opens the door to far more flexible photonic systems,” said Namkyoo Park.

Co-first authors Dr. Seungkyun Park of the KAIST InnoCORE PICORE Center and SNU’s Photonic Systems Laboratory, and PhD student Beomjoon Chae of SNU’s Intelligent Wave Systems Laboratory, verified the design through numerical and three-dimensional electromagnetic simulations on a silicon nitride platform, accounting for material losses, resonator quality variations, backscattering, coupling fluctuations, phase errors, and thermal crosstalk.

The research was supported by South Korea’s Ministry of Science and ICT through its IRC, BRL, and Young Researcher programs, and was published June 30 in Advanced Science.

Journal: Advanced Science
DOI: 10.1002/advs.76378
Article Title: Fully programmable slow light based on a spinor representation of generalized coupled-resonator-induced transparency
Publication Date: June 28, 2026

Source: EurekAlert