Abstract
Simultaneous amplitude and frequency stabilization of an internal-mirror He-Ne laser (λ=633nm) by a fan cooling method was studied at different laser-tube positions. The total back beam intensity is fed back to control the cavity length of the laser tube. Since the temperatures of the laser tube vary according to the position, its stabilization properties also vary. At the fore part of the laser tube, the relative amplitude stability was found to be ±0.08 % and the relative frequency stability to be ±5×10-9 over a period of 10 minutes or longer. At the hinder part of the laser tube, the relative amplitude stability was ±0.05 % and the rela tive frequency stability was ±3×10-9 over a period of 10 minutes or longer.
