Analytical expression for the nth Fourier coefficient of a modulated Lorentzian dispersion lineshape function

作者：Westberg Jonas; Kluczynski Pawel; Lundqvist Stefan; Axner Ove^*

来源：Journal of Quantitative Spectroscopy and Radiative Transfer, 2011, 112(9): 1443-1449.

DOI：10.1016/j.jqsrt.2011.02.007

• Modulated Lorentzian dispersion lineshape
• Fourier coefficient
• Phase-sensitive detection
• Faraday modulation/rotation spectrometry
• FAMOS/FRS
• NICE-OHMS

Modulated spectroscopic detection techniques that rely on dispersion, e.g. Faraday modulation/rotation spectroscopy and wavelength-modulated noise-immune cavity-enhanced optical heterodyne molecular spectroscopy, are often described in terms of Fourier coefficients of a modulated dispersion lineshape function. This work derives a non-complex analytical expression for the nth Fourier coefficient of a modulated Lorentzian dispersion lineshape function. The expression is easier to implement, and orders of magnitude faster to execute, than previous approaches involving numerical calculations of integrals. The first six Fourier coefficients are explicitly given and illustrated for their optimum modulation amplitudes, which are also given.

• 出版日期2011-6