Berlin 2014 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 30: Poster: Photonics, laser development and applications, ultrashort laser pulses, quantum effects
Q 30.50: Poster
Tuesday, March 18, 2014, 16:30–18:30, Spree-Palais
Relative Intensity Noise Reduction of a Quantum Cascade Laser by Optical Feedback — •Carsten Juretzka1, Stefan Breuer1, Lukas Drzewietzki1, Florian Michel1, Mathieu Carras2, and Wolfgang Elsäßer1 — 1Institut für Angewandte Physik, Technische Universität Darmstadt, Schloßgartenstr. 7, Darmstadt 64289, Germany — 2III-V Lab, Campus Polytechnique, F-91767 Palaiseau Cedex, France
Quantum cascade lasers (QCL) are highly promising versatile mid-infrared sources for high-precision spectroscopy involving fundamental molecular absorption lines. The detection sensitivity is thereby limited by the noise of QCL and driving electronics. Here, we demonstrate the reduction of laser relative intensity noise (RIN) by applying an optical feedback technique that impacts the statistical noise properties of the QCL. The QCL in these experiment is a DFB structure emitting at 5.7 µm. Varying the feedback strength, feedback-phase and laser current, we identify a substantial reduction of RIN by -9.5 dB within a broad frequency range 200 kHz compared to the QCL without feedback. These results can be well explained by the concept of detuned loading [1]. Future work will cover the realization of synchronized wavelength-tuning and feedback-phase control. [1] C. Juretzka, S. Breuer, L. Drzewietzki, F. Schad, M. Carras and W. Elsäßer, 9.5 dB relative intensity noise reduction in quantum cascade laser by detuned loading, Electronics Letters, Volume 49, p. 1548-1550, 2013