Correction: Hofstetter et al. Monolithically Integrated Michelson Interferometer Using an InGaAs/InAlAs Quantum Cascade Laser at λ = 4 µm. Photonics 2024, 11, 593

There was an error in the original publication [1]. We did not define the abbreviation for “quantum cascade”, which is “(QC)”. In addition, the article “a” should also be added five words before the missing abbreviation. The following correction has been made to “1. Introduction, Paragraph Number 5”:

However, since the alignment of the externally moving mirror in a visible wavelength Michelson interferometer (such as the version from the year 1995/96) is not at all trivial—especially because of the small waveguide dimensions—here, we suggest the use of a mid-infrared quantum cascade (QC) laser emitting radiation at a wavelength of 4 µm.

In the original publication, the following paper was not cited: Hofstetter, D.; Beck, M.; Faist, J. Quantum-cascade-laser structures as photodetectors. Appl. Phys. Lett. 2002, 81, 2683–2685. https://doi.org/10.1063/1.1512954. The citation has now been inserted in “3. Results, Paragraph Number 3” and should read as follows:

On both sides adjacent to the single-mode DFB laser light source, two photodetectors labeled ‘Photodetector 1’ at the top and ‘Photodetector 2’ at the bottom are shown [36].

In addition to the already existing references, we now also refer to our own paper from 2002, describing the use of quantum cascade lasers as photodetectors. With this correction, the order of all references starting from reference [36] has to be adjusted accordingly.

The authors state that the scientific conclusions are unaffected. This correction was approved by the Academic Editor. The original publication has also been updated.