Open AccessReversible switching of quantum cascade laser-modes using a pH-responsive polymeric cladding as transducer
Author(s) -
B. Basnar,
S. Schartner,
M. Austerer,
A. M. Andrews,
T. Roch,
W. Schrenk,
G. Strasser
Publication year - 2008
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.16.008557
Subject(s) - materials science , cladding (metalworking) , laser , optoelectronics , optics , polymer , wavelength , quantum cascade laser , cascade , absorption (acoustics) , polyacrylic acid , chemistry , physics , chromatography , terahertz radiation , metallurgy , composite material
We present a novel approach for the reversible switching of the emission wavelength of a quantum cascade laser (QCL) using a halochromic cladding. An air-waveguide laser ridge is coated with a thin layer of polyacrylic acid. This cladding introduces losses corresponding to the absorption spectrum of the polymer. By changing the state of the polymer, the absorption spectrum and losses change, inducing a shift of 7 cm(-1) in the emission wavelength. This change is induced by exposure to acidic or alkaline vapors under ambient conditions and is fully reversible. Such lasers can be used as multi-color light source and as sensor for atmospheric pH.