Fourier Line-Shape Analysis
(a) Unapodized and apodized absorbance spectrum of LiY1-xHoxF4 (𝑥=0.3%) with 0.001 cm−1 resolution at a temperature T = 3.8 K, exhibiting an eightfold repeated signal due to the I = 7/2 nuclear hyperfine levels of the Ho atoms. The BH4T apodization function is centered at the spectrum and decays to zero on its ends. (b) DFT coefficient |ck| of data shown in (a). Inset: The characteristic pattern decays within the first 600 Fourier components. Around 𝑘=1440 and 𝑘=2240 there are strong noise contributions from Fabry-Perot interference due to reflecting optical components.
Lineshape analysis is a recurrent task in solid-state and atomic physics, chemistry and bio-medicine. When noise is present it is often computationally intensive, even more so for multiple peaks. We demonstrate an algorithm which takes advantage of peak multiplicity (N) to retrieve line shape information. The method is exemplified via analysis of Lorentzian and Gaussian contributions to individual lineshapes for a practical spectroscopic measurement, and benefits from a linear increase in sensitivity with the number N.
Recent Publications
Taking advantage of multiplet structure for lineshape analysis in Fourier space
A. Beckert, H. Sigg, G. Aeppli
external pageOpt. Express 28, 24937 (2020)