Abstract
A simple method is demonstrated for internal intensity modulation of the 3.391 and 3.392-μm emissions of a He−Ne laser with equal amplitudes and 180° out of phase to each other. A modulation amplitude of 0.7 mW peak-to-peak at 1kHz for the individual emissions has been obtained from a laser plasma tube 50 cm long while maintaining the total-intensity modulation as low as 0.25 μW for a signal averaging time of 1 s. This laser source can greatly simplify the setup and improve the sensitivity of differential absorption measurements for the methane remote sensing.
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References
H.J. Gerritsen, S.A. Ahmed: Phys. Lett13, 41 (1964)
B.N. Edwards, D.E. Burch: J. Opt. Soc. Am.55, 174 (1965)
C.B. Moore: Appl. Opt.4, 252 (1965)
H.J. Gerritsen: Trans. Soc. Min. Eng. AIME235, 428 (1966)
V.I. Makhorin, A.I. Popov, E.D. Protsenko: Sov. J. Quant. Electron.3, 24 (1973)
V.A. Balakin, I.P. Konovalov, A.I. Ocheretyanyi, A.I. Popov, E.D. Protsenko: Sov. J. Quant. Electron.5, 230 (1975)
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Uehara, K. Alternate intensity modulation of a dual-wavelength He−Ne laser for differential absorption measurements. Appl. Phys. B 38, 37–40 (1985). https://doi.org/10.1007/BF00691768
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DOI: https://doi.org/10.1007/BF00691768