Development of CO2 laser dispersion interferometer with photoelastic modulator

T. Akiyama, K. Kawahata, S. Okajima, K. Nakayama
2010 Review of Scientific Instruments  
A dispersion interferometer is one of the promising methods of the electron density measurement on large and high density fusion devices. This paper describes development of a CO 2 laser dispersion interferometer with a photoelastic modulator for phase modulation. In order to make the dispersion interferometer free from variations of the detected intensity, a new phase extraction method is introduced: The phase shift is evaluated from a ratio of amplitudes of the fundamental and the second
more » ... and the second harmonics of the phase modulation frequency in the detected interference signal. The proof-of-principle experiments demonstrate the feasibility of this method.
doi:10.1063/1.3460453 pmid:21033856 fatcat:kthpby7ec5efndhcfzeucqbtjm