Open AccessAll-optical phase modulation for integrated interferometric biosensors
Author(s) -
Stefania Dante,
Daphné Duval,
Borja Sepúlveda,
Ana Belén González-Guerrero,
José Ramón Sendra Sendra,
Laura M. Lechuga
Publication year - 2012
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.007195
Subject(s) - optics , phase modulation , interferometry , intensity modulation , modulation (music) , phase noise , astronomical interferometer , optical power , signal (programming language) , physics , materials science , laser , computer science , acoustics , programming language
We present the theoretical and the experimental implementation of an all-optical phase modulation system in integrated Mach-Zehnder Interferometers to solve the drawbacks related to the periodic nature of the interferometric signal. Sensor phase is tuned by modulating the emission wavelength of low-cost commercial laser diodes by changing their output power. FFT deconvolution of the signal allows for direct phase readout, immune to sensitivity variations and to light intensity fluctuations. This simple phase modulation scheme increases the signal-to-noise ratio of the measurements in one order of magnitude, rendering in a sensor with a detection limit of 1.9·10⁻⁷ RIU. The viability of the all-optical modulation approach is demonstrated with an immunoassay detection as a biosensing proof of concept.