Dataset for Gas spectroscopy with integrated frequency monitoring through self-mixing in a terahertz quantum-cascade laser.

This archive contains the dataset associated with the publication entitled 'Gas spectroscopy with integrated frequency-monitoring through self-mixing in a terahertz quantum-cascade laser';. In this work, we demonstrate a gas spectroscopy technique based on self-mixing interferometry in a 3.4-THz quantum-cascade laser (QCL). All previous QCL spectroscopy techniques have required additional THz instrumentation (detectors, mixers or spectrometers) for system-precalibration or in situ spectral analysis. By contrast, our system self-calibrates the laser frequency to a precision of 630 MHz (0.02%) by analyzing voltage perturbations across the QCL, in response to optical feedback from a mirror mounted on a 0-800-mm round-trip delayline. We demonstrate spectroscopy of methanol by introducing a gas cell into the feedback path, and show that a limiting absorption coefficient of ~0.0001 /cm is resolvable. This dataset includes the raw data used to generate all figures within the publication.