This unit measures electromagnetic wave frequencies at one quadrillion hertz (10¹⁵ Hz). It falls squarely in the ultraviolet and visible light regions of the electromagnetic spectrum. Physicists and photonics engineers use it when discussing ultrafast lasers, optical computing, and electron dynamics in semiconductors.
Heard on the job
The new optical switch operates in the lower petahertz range, completely bypassing the thermal limits of silicon.