Frequency Tuning and Modulation of a Quantum Cascade Laser with an Integrated Resistive Heater
AbstractWe present a detailed experimental investigation of the use of a novel actuator for frequency tuning and modulation in a quantum cascade laser (QCL) based on a resistive integrated heater (IH) placed close to the active region. This new actuator is attractive for molecular spectroscopy applications as it enables fast tuning of the QCL wavelength with a minor influence on the optical output power, and is electrically-controlled. Using a spectroscopic setup comprising a low-pressure gas cell, we measured the tuning and modulation properties of a QCL emitting at 7.8 μm as a function of the active region and IH currents. We show that a current step applied to the IH enables the laser frequency to be switched by 500 MHz in a few milliseconds, as fast as for a step of the current in the active region, and limited by heat dissipation towards the laser sub-mount. The QCL optical frequency can be modulated up to ~100 kHz with the IH current, which is one order of magnitude slower than for the QCL current, but sufficient for many spectroscopic applications. We discuss the experimental results using a thermal model of the heat transfer in terms of cascaded low-pass filters and extract the respective cut-off frequencies. Finally, we present a proof-of-principle experiment of wavelength modulation spectroscopy of a N2O transition performed with a modulation of the IH current and show some potential benefits in comparison to QCL current modulation, which results from the reduced associated amplitude modulation. View Full-Text
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Gürel, K.; Schilt, S.; Bismuto, A.; Bidaux, Y.; Tardy, C.; Blaser, S.; Gresch, T.; Südmeyer, T. Frequency Tuning and Modulation of a Quantum Cascade Laser with an Integrated Resistive Heater. Photonics 2016, 3, 47.
Gürel K, Schilt S, Bismuto A, Bidaux Y, Tardy C, Blaser S, Gresch T, Südmeyer T. Frequency Tuning and Modulation of a Quantum Cascade Laser with an Integrated Resistive Heater. Photonics. 2016; 3(3):47.Chicago/Turabian Style
Gürel, Kutan; Schilt, Stéphane; Bismuto, Alfredo; Bidaux, Yves; Tardy, Camille; Blaser, Stéphane; Gresch, Tobias; Südmeyer, Thomas. 2016. "Frequency Tuning and Modulation of a Quantum Cascade Laser with an Integrated Resistive Heater." Photonics 3, no. 3: 47.
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