| Full text | |
| Author(s): |
Vallini, Felipe
[1]
;
Gu, Qing
[2]
;
Kats, Michael
[2]
;
Fainman, Yeshaiahu
[2]
;
Frateschi, Newton C.
[1]
Total Authors: 5
|
| Affiliation: | [1] Univ Campinas UNICAMP, GlebWataghin Phys Inst, Dept Appl Phys, Device Res Lab, BR-13083859 Campinas, SP - Brazil
[2] Univ Calif San Diego, Dept Elect & Comp Engn, La Jolla, CA 92093 - USA
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | Optics Express; v. 21, n. 22, p. 25985-25998, NOV 4 2013. |
| Web of Science Citations: | 5 |
| Abstract | |
Although multi quantum well (MQW) structure is frequently suggested as the appropriate medium for providing optical gain in nanolasers with low threshold current, we demonstrate that in general bulk gain medium can be a better choice. We show that the high threshold gain required for nanolasers demands high threshold carrier concentrations and therefore a highly degenerate condition in which the barriers between the quantum wells are heavily pumped. As a result, there occurs spontaneous emission from the barrier in very dissipative low Q modes or undesired confined higher Q modes with resonance wavelengths close to the barrier bandgap. This results in a competition between wells and barriers that suppresses lasing. A complete model involving the optical properties of the resonant cavity combined with the carrier injection in the multilayer structure is presented to support our argument. With this theoretical model we show that while lasing is achieved in the nanolaser with bulk gain media, the nanolaser with MQW gain structure exhibits well emission saturation due to the onset of barrier emission. (C) 2013 Optical Society of America (AU) | |
| FAPESP's process: | 05/51689-2 - Optics and Photonics Research Center at UNICAMP |
| Grantee: | Hugo Luis Fragnito |
| Support Opportunities: | Research Grants - Research, Innovation and Dissemination Centers - RIDC |