He-Ne Laser-Beam Deviation with Thermal Distorsion

Abstract

Laser-beam deviation with thermal distortion of an internal-mirror He-Ne (λ= 633 nm) laser is measured using a two-dimensional position sensitive device. Typical values of beam deviation for a He-Ne laser are around±50 μrad for operation from a cold start, and depend on the twist angle of a laser tube. The values of beam deviation for an output and frequency stabilized He-Ne laser are ±3 μrad/h in the vertical direction and ±5 μrad/h in the transverse direction. The tube length of the stabilized laser is controlled to be constant, and also the laser-beam deviation is stabilized.