A first-of-its-kind chip features both a laser and waveguide to create a photonic integrated circuit

https://phys.org/news/2023-08-first-of-its-kind-chip-features-laser-waveguide.html

" atomic clocks and could also be used in quantum applications. It would also reduce the need for huge optical tables... insert isolators prevent reflections... ultralow-loss silicon nitride waveguide on silicon substrate covered with silicon over which mounted low-noise indium phosphate laser... separating 2 components prevented damage to the waveguide during etching... silicon nitride redistribution layer for interactions between 2 components via evanescent fields... tunable microwave frequency generator"

Related:

The laser trick that could put an ultraprecise optical clock on a chip
https://www.nature.com/articles/d41586-023-03782-0

Researchers use liquid crystals to control polarization inside laser-written waveguides
https://phys.org/news/2024-03-liquid-crystals-polarization-laser-written.html