Near-field imaging of quantum cascade laser transverse modes


Nanfang Yu, Laurent Diehl, Ertugrul Cubukcu, Christian Pfluegl, Bour David, Corzine Scott, Jintian Zhu, Gloria Hoefler, Kenneth B. Crozier, and Federico Capasso. 2007. “Near-field imaging of quantum cascade laser transverse modes.” OPTICS EXPRESS, 15, 20, Pp. 13227-13235. Publisher's Version
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We report near field imaging of the transverse lasing modes of quantum cascade lasers. A mid-infrared apertureless near-field scanning optical microscope was used to characterize the modes on the laser facet. A very stable mode pattern corresponding to a TM00 mode was observed as function of increasing driving current for a narrow active region quantum cascade laser. Higher order modes were observed for devices with a larger active region width-to-wavelength ratio operated in pulsed mode close to threshold. A theoretical model is proposed to explain why specific transverse modes are preferred close to threshold. The model is in good agreement with the experimental results. (C) 2007 Optical Society of America.
Last updated on 05/23/2020