Open AccessQuantum cascade laser gain enhancement by front facet illumination
Author(s) -
Gang Chen,
C. G. Bethea,
Rainer Martini
Publication year - 2009
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.17.024282
Subject(s) - optics , laser , materials science , cascade , quantum cascade laser , optoelectronics , gain , laser power scaling , infrared , far infrared laser , active laser medium , physics , chemistry , chromatography
Optical gain enhancement is demonstrated in a standard mid-infrared quantum cascade laser in pulse operation, using a near infrared illumination on the laser facet. An increase in the laser emission is observed, as well as greater dynamic range, threshold reduction, and a blue shift in the laser cavity modes. The optically induced gain increase allows for optical switching of the laser. All the changes have a nonlinear dependency on the illumination optical power and are attributed to the free carrier concentration increase and the electron transport change in the active region due to the near infrared illumination.