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Ultrastable Laser Array at 633 nm for Real-Time Dimensional Metrology



Y Lecoq, J Pedulla, John Lawall


We describe a laser system for very high-accuracy dimensional metrology. A sealed-cavity helium-neon laser is offset-locked to an iodine-stabilized laser in order to realize a secondary standard with higher power and less phase noise. Synchronous averaging is employed to remove the effect of the frequency modulation present on the iodine-stabilized laser. Additional lasers are offset-locked to the secondary standard for use in interferometry. All servo loops are implemented digitally. The offset-locked lasers have intrinsic linewidths of the order of 2.5 kHz and exhibit a rms deviation from the iodine-stabilized laser below 18 kHz. The amplitude noise is at the shot-noise limit for frequencies above 700 kHz. We describe and evaluate the system in detail, and include a discussion of the noise associated with various types of power supplies.
Review of Scientific Instruments


helium-neon laser, iodine-stabilized laser, stabilized laser


Lecoq, Y. , Pedulla, J. and Lawall, J. (2001), Ultrastable Laser Array at 633 nm for Real-Time Dimensional Metrology, Review of Scientific Instruments (Accessed March 2, 2024)
Created December 31, 2000, Updated October 12, 2021