eXtended Tuning Laser

Alpes Lasers offers two types of extended tuning devices, both of which allow rapid tuning at fixed temperature in a wider range than standard DFB lasers. The QC-ET allows fully continuous tuning over 0.4% of the central wavelength, while the QC-XT described here allows piece-wise continuous tuning over 2% of the central wavelength (40 cm-1 at 5 μm).

QC-XT Laser Sources are controlled by three independent current inputs. Two inputs control the front and back mirrors of the cavity (IF and IB).The laser itself is driven by the laser current IL and behaves as a normal DFB laser with the available range modified by the values of IF and IB.

By using different mirror configurations, the laser can be rapidly switched between different configurations, allowing rapid multi-point sampling and/or scanning. In this way, the system can act as several DFB lasers on the same chip, with the DFB range selection operated by the mirror configurations.

Key Benefits:

• Wavelength and power independent control
• Direct access to any wavelength
• Extended tuning range at constant heat-sink temperature
• Increased wavelength scanning span fully  electrically (Increased electrical wavelength scan)
• Possibility of arbitrary scanning scheme
• DFB wavelength reproducibility
• DFB linewidth and noise

To get more information about the technology behind the QC-XT lasers you can read the following papers:

• Y. Bidaux, A. Bismuto, C. Tardy, R. Terazzi, T. Gresch, S. Blaser, A. Muller, and J. Faist, “Extended and quasi-continuous tuning of quantum cascade lasers using superstructure gratings and integrated heaters,” Applied Physics Letters, vol. 107, no. 22, p. 221108, Nov. 2015.
• A. Zifarelli et al., “Quartz-enhanced photoacoustic spectroscopy employing a Vernier-effect distributed feedback-quantum cascade laser for multiple analytes detection”, Proc. SPIE 12021, Novel In-Plane Semiconductor Lasers XXI, 120210E, Mar. 2022.
• A. Zifarelli et al.,, “Multi-gas quartz-enhanced photoacoustic sensor for environmental monitoring exploiting a Vernier effect-based quantum cascade laser”, Photoacoustics 28 (2022)
• Raphael Brechbühler et al., “Rapid Detection of Volatile Organic Compounds by Switch–Scan Tuning of Vernier Quantum-Cascade Lasers“, Anal. Chem. 2023
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