Amplitude modulation of the cw laser light in the TEM mn mode by means of a mechanical chopper
Amplitude modulation of the laser beam in a TEM mn mode by means of a mechanical chopper is investigated on the basis of the chopping model represented by a moving system of infinitely long, parallel slots and mark spaces. The cases of rectangular and axial symmetry of the laser beam are both treated. The explicit expressions for the waveform of the modulated normalized transmitted laser power are deduced and their consequences investigated. It is found that in the case of rectangular symmetry, unlike the case of axial symmetry, the TEM mn modes give, for a constant value of the mode numbern and for any value ofm, the same time dependence of the amplitude modulated laser power. The notion of the equivalent modulation widths is introduced and conditions for the efficient amplitude modulation are found.
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- 1.V.S. Letokhov, V.P. Zharov:Opto-Acoustic Modulation Spectroscopy, Springer Ser. Opt. Sci.37 (Springer, Berlin, Heidelberg 1985)Google Scholar
- 2.Y.H. Pao (ed):Optoacoustic Spectroscopy and Detection (Academic, New York 1977)Google Scholar
- 3.A. Rosencwaig:Photoacoustics and Photoacoustic Spectroscopy (Wiley, New York 1980)Google Scholar
- 4.G.A. West, J.J. Barrett, D.R. Siebert, K. Virupaksha Reddy: Rev. Sci. Instrum.54, 797–817 (1983)Google Scholar
- 5.I. Mendaš, P. Vujković Cvijin: Appl. Phys. B32 119–122 (1983)Google Scholar
- 6.I. Mendaš, P. Vujković Cvijin, D. Ignjatijević: Appl. Phys. B34, 1–4 (1984)Google Scholar
- 7.H. Kogelnik, T. Li: Appl. Opt.5, 1550–1567 (1966)Google Scholar
- 8.H.K.V. Lotsch: Optik30, 1–14, 181–201, 217–233, and 563–576 (1969/70)Google Scholar
- 9.I.S. Gradstheyn, I.M. Ryzhik: Tables of Integrals, Series and Products (in Russian) (Nauka, Moscow 1971) Eqs. (7.374) and (7.414)Google Scholar
- 10.M. Abramowitz, I.A. Stegun (eds.):Handbook of Mathematical Functions (Dover, New York 1970), pp. 299 and 775Google Scholar