Magnet-Free Chip Isolator Blocks Back-Reflections by 30 dB Across 30 nm
Updated
Updated · Nature.com · Aug 14
Magnet-Free Chip Isolator Blocks Back-Reflections by 30 dB Across 30 nm
3 articles · Updated · Nature.com · Aug 14
Summary
Researchers experimentally demonstrated an on-chip travelling-wave optical isolator that reached about 30.6 dB isolation at 789.7 nm while leaving forward-going light essentially unchanged.
The device uses radio-frequency electro-optic modulation across four parallel waveguides to create dynamic rotating destructive interference, cancelling backward-propagating light without magnets, resonators or detectable sidebands.
Tests showed more than 24 dB isolation across 770-800 nm with thermo-optic tuning, and more than 20 dB for two lasers at once within a 10 nm window without adjustment.
Built on a foundry-compatible silicon nitride and bonded lithium-niobate platform, the design fabricated 171 isolators on a 100-mm wafer and targets scalable production.
The 770-800 nm span covers key alkali-atom transitions, positioning the component for integrated atomic clocks, quantum sensors, spectroscopy systems and telecom photonics.