Laser frequency stabilization based on control of intermode beat note

A new frequency-stabilized two-mode laser was introduced. Based on the relationship between optical frequency and intermode beat note, the intermode beat note was locked to the radio frequency standard by precise phase-locking technique to keep the cavity stable, so laser frequency stabilization was realized. Theoretical analysis shows that the stability of the laser frequency is identical with that of the intermode beat note. Experimentally, the intermode beat note of He-Ne laser was precisely locked to the radio frequency standard, and the laser frequency was also locked. The frequencies of two frequency-stabilized He-Ne lasers were compared. The result showed that the laser had a frequency stability of 5 × 10^-10 at 1 s of averaging time and 5 × 10^-11 in 100 s of averaging time.