Title :
Improved CW operation of quantum cascade lasers with epitaxial-side heat-sinking
Author :
Gmachl, Claire ; Sergent, A. Michael ; Tredicucci, Alessandro ; Capasso, Federico ; Hutchinson, Albert L. ; Sivco, Deborah L. ; Baillargeon, James N. ; Chu, S.N.George ; Cho, Alfred Y.
Author_Institution :
Lucent Technol., AT&T Bell Labs., Murray Hill, NJ, USA
Abstract :
First results on the epilayer-side mounting of quantum cascade (QC) lasers are presented. Operated in continuous-wave (CW) mode, these lasers are superior to substrate-bonded devices. The maximum CW temperature is raised by 20 K (up to 175 K), and, at comparable heat sink temperatures, the performance with respect to threshold current, output power, and slope efficiency is greatly improved for the epilayer-side mounted devices. QC-laser-specific mounting procedures are discussed in this letter, such as the high reflectivity coating of the back-facet and the front-facet cleaving after mounting. Modeling of the temperature distribution inside the QC laser shows a strong temperature gradient within the active waveguide core, which partly explains the still low maximum CW operating temperatures.
Keywords :
heat sinks; laser modes; quantum well lasers; reflectivity; temperature distribution; CW mode; QC-laser-specific mounting procedures; active waveguide core; back-facet; comparable heat sink temperatures; epilayer-side mounted devices; epilayer-side mounting; epitaxial-side heat-sinking; front-facet cleaving; high reflectivity coating; improved CW operation; low maximum CW operating temperatures; maximum CW temperature; output power; quantum cascade lasers; slope efficiency; strong temperature gradient; temperature distribution; threshold current; Coatings; Heat sinks; Laser modes; Power generation; Quantum cascade lasers; Reflectivity; Temperature distribution; Threshold current; Waveguide components; Waveguide lasers;
Journal_Title :
Photonics Technology Letters, IEEE
