Frequency Locking of 543 nm He–Ne Laser on Iodine Spectrum

Frequency tuning of internal-mirror 543 nm He–Ne lasers was realized using a piezo-electric transducer (PZT) through an elastic deformation of the laser tube. Two 543 nm He–Ne lasers were locked on the saturated absorption lines of iodine with the third-derivative signal of a signal-to-noise ratio of about 50. From the beat signal between them the frequency stability was measured to be σ(τ, 2)=1.2×10-11τ-1/2(10-4 s