The 2005 Nobel Prize in Physics was awarded to Theodor W. Hänsch and John L. Hall "for their contributions to the development of laser-based precision spectroscopy, including the optical frequency comb technique."

Optical frequency combs are lasers with locked repetition rates. The Optical Frequency Comb Teaching & Research System developed by Jiuzhang Quantum can stably lock the repetition frequency output by the seed source to a radio frequency (RF) reference source (rubidium atomic clock). The system uses a photodetector to convert the laser pulse repetition frequency signal into an electrical signal, compares it with the RF reference, and controls the internal cavity temperature and piezoelectric ceramics (PZT) to stretch the fiber via a highly responsive phase-locked loop (PLL), achieving stable repetition rate locking.