Time series analysis of duty cycle induced randomness in thermal lens system

Vimal Raj (Author), Mohanachandran Nair Sindhu Swapna (Author), K. Satheesh Kumar (Author), Sankaranarayana Iyer Sankararaman (Author)

Abstract

The present work employs time series analysis, a proven powerful mathematical tool, for investigating the complex molecular dynamics of the thermal lens (TL) system induced by the duty cycle (C) variation. For intensity modulation, TL spectroscopy commonly uses optical choppers. The TL formation involves complex molecular dynamics that vary with the input photothermal energy, which is implemented by varying the duty cycle of the chopper. The molecular dynamics is studied from the fractal dimension (D), phase portrait, sample entropy (S), and Hurst exponent (H) for different duty cycles. The increasing value of C is found to increase D and S, indicating that the system is becoming complex and less deterministic, as evidenced by the phase portrait analysis. The value of H less than 0.5 conforms the evolution of the TL system to more anti-persistent nature with C. The increasing value of C increases the enthalpy of the system that appears as an increase in full width at half maximum of the refractive index profile. Thus the study establishes that the sample entropy and thermodynamic entropy are directly related.

Keywords

time series analysis;fractal analysis;photothermal lens spectroscopy;fractal dimension;

Data

Language:	English
Year of publishing:	2020
Typology:	1.01 - Original Scientific Article
Organization:	UNG - University of Nova Gorica
UDC:	54
COBISS:	113801475
ISSN:	0030-4026
Views:	456
Downloads:	0
Average score:	0 (0 votes)
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Other data

URN:	URN:SI:UNG
Type (COBISS):	Not categorized
Pages:	str. 1-5
Issue:	ǂVol. ǂ212
Chronology:	Jun. 2020
DOI:	10.1016/j.ijleo.2020.164720
ID:	15832539