Overcoming Brillouin cascading by burning nm-scale Bragg gratings directly inside laser's optical cavity, creating dead zone blocking parasitic loss

https://phys.org/news/2025-11-nanoscale-bragg-photonic-chips-suppress.html

"produces narrow spectrum light... eliminates lasers' noise source... photonic bandgap removes states' density parasitic modes rely on to operate... induced dead zone causes 6X increase in Brillouin lasing's minimum energy threshold for exciting laser emission, 2.5X power, boost... Bragg gratings can be written, erased, re-tuned after creation using only laser light, for low-noise single-mode or cascaded multi-mode operation... general framework for controlling optical processes on photonic chips, not only Brillouin lasers"