Enhancement of quantum cascade laser intersubband transitions via coupling to resonant discrete photonic modes of subwavelength gratings

We present an optical spectroscopic study of InGaAs/AlInAs active region of quan-tum cascade lasers grown by low pressure metal organic vapor phase epitaxy combined with subwavelength gratings fabricated by reactive ion etching. Fourier-transformed photolumines-cence measurements were used to compare the emission properties of structures before , after processing the gratings. Our results demonstrate a significant increase of the photoluminescence intensity related to intersubband transitions in the mid-infrared, which is attributed to coupling with the grating modes via so called photonic Fano resonances. Our findings demonstrate a promising method for enhancing the emission in optoelectronic devices operating in a broad range of application-relevant infrared.Published by Optica Publishing Group under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation , DOI.