The handedness of light holds the key to better optical control

https://phys.org/news/2022-07-handedness-key-optical.html

"Current optical modulators mainly use electrical or acoustic effects to modulate light's properties indirectly. These two traditional optical modulator technologies can control the properties of light at nanosecond speeds . Our all-optical modulator, which uses a coherent optical process, can work at femtosecond speeds, or about a million times faster, Zhang notes"