]>Remote System for Detection of Low-Levels of Methane Based on Photonic Crystal Fibres and Wavelength Modulation Spectroscopy : Figure 6
398403.fig.006a
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398403.fig.006b
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Figure 6: (a) Wavelength modulation converted to amplitude modulation in Wavelength Modulation Spectroscopy; (b) spectral contents of the optical signal: (i) laser unmodulated; (ii) laser modulated with no absorption; (iii) laser modulated with absorption.