Open AccessGeneralized lock-in detection for interferometry: application to phase sensitive spectroscopy and near-field nanoscopy
Author(s) -
Abeer Al Mohtar,
Julien Vaillant,
Zohreh Sedaghat,
M. Kazan,
Lilian Joly,
C. Stoeffler,
Jean-Christophe Cousin,
A. Z. Khoury,
Aurélien Bruyant
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.022232
Subject(s) - optics , interferometry , phase modulation , phase (matter) , physics , amplitude , modulation (music) , frequency modulation , astronomical interferometer , signal (programming language) , amplitude modulation , spectroscopy , field (mathematics) , phase noise , computer science , acoustics , telecommunications , bandwidth (computing) , mathematics , quantum mechanics , pure mathematics , programming language
A generalized lock-in detection method is proposed to extract amplitude and phase from optical interferometers when an arbitrary periodic phase or frequency modulation is used. The actual modulation function is used to create the reference signals providing an optimal extraction of the useful information, notably for sinusoidal phase modulation. This simple and efficient approach has been tested and applied to phase sensitive spectroscopy and near-field optical measurements. We analyze the case where the signal amplitude is modulated and we show how to suppress the contribution of unmodulated background field.