We demonstrate a common-path optical interferometer based on a quantum-cascade laser (QCL), in which the QCL acts both as source and detector of the infrared radiation. The collinear arms of the interferometer are terminated by a plastic surface (acting as the beam splitter) and by a metallic one (acting as the mirror). The different reflectivity of the surfaces allows for high contrast feedback-interferometry fringes exhibited on the laser-emitted power and revealed by voltage compliance measurement at the QCL terminals. The displacement of each surface can be identified and measured with sub wavelength resolution. The experimental results are in excellent agreement with the numerical simulations based on the Lang-Kobayashi model for multiple cavities. Applications to microfluidics and resonant chemical detection can be envisaged.
Single QCL-based sensor measuring the simultaneous displacement of independent targets
Columbo Lorenzo;Mezzapesa Francesco P;Brambilla Massimo;
2013
Abstract
We demonstrate a common-path optical interferometer based on a quantum-cascade laser (QCL), in which the QCL acts both as source and detector of the infrared radiation. The collinear arms of the interferometer are terminated by a plastic surface (acting as the beam splitter) and by a metallic one (acting as the mirror). The different reflectivity of the surfaces allows for high contrast feedback-interferometry fringes exhibited on the laser-emitted power and revealed by voltage compliance measurement at the QCL terminals. The displacement of each surface can be identified and measured with sub wavelength resolution. The experimental results are in excellent agreement with the numerical simulations based on the Lang-Kobayashi model for multiple cavities. Applications to microfluidics and resonant chemical detection can be envisaged.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
