Abstract
In order to eliminate air-turbulence-induced errors in the measurement of linear displacement, an interferometer with two different laser beams using second harmonic generation (SHG) has been developed. These beams have wavelengths of 488 nm, emitted from an Ar+ laser, and 244 nm, which is the second harmonic generated by a nonlinear crystal β-BaB2O4 inserted in the Ar+ laser cavity. Demonstration experiments have proven the system's efficacy in eliminating air-turbulence-induced errors.