Current- and Temperature-Induced Beam Steering in 7.8- m Emitting Quantum-Cascade Lasers

• Published in: IEEE journal of quantum electronics Vol. 44; no. 11; pp. 1124 - 1128
• Main Authors: Hinkov, B., Fuchs, F., Bronner, W., Kohler, K., Wagner, J.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-11-2008; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Beam steering; Chemical lasers; Gas lasers; infrared emission; Laser beams; Laser modes; lateral modes; Optical design; Optical resonators; Quantum cascade lasers; Quantum well lasers; quantum-cascade (QC) laser; Spectroscopy; time-resolved spectroscopy
• ISSN: 0018-9197; 1558-1713
• DOI: 10.1109/JQE.2008.2003499

We report large current- and temperature-induced beam-steering effects, observed in the far-field distribution of InP-based quantum-cascade lasers emitting around 7.8-mum wavelength operated in pulsed mode. Changing the temperature within a narrow range of ~10degC around room-temperature leads to a change in the direction of the output beam, as given by the central lobe in the far-field intensity distribution, from +11deg to -13deg as measured relative to the resonator axis. This beam steering effect is linked to changes in the lateral mode distribution, as revealed by time-resolved spectroscopy of the lasing spectrum.