Lateral current injection (LCI) multiple quantum-well 1.55 mu m laser with improved gain uniformity across the active region
2004 (English)In: Optical and quantum electronics, ISSN 0306-8919, E-ISSN 1572-817X, Vol. 36, no 9, 827-846 p.Article in journal (Refereed) Published
A simulation study of lateral current injection 1.55 mum laser with strain-compensated multiple quantum-well (MQW) active region (InGaAsP well, InGaAlAs barrier) is presented using self-consistent 2D numerical simulations. The effects of different mesa width and p-doping in the QWs on the carrier and gain uniformity across the active region are explored. A high p-doping in the quantum wells is found to increases the carrier and gain non-uniformity across the active region. The QW region close to the n-contact side does not provide much gain at high optical powers. An asymmetric optical waveguide design is proposed to help reduce the gain non-uniformity across the active region. By shifting the optical modal peak toward the p-side, the modal overlap between the gain region and the optical mode is improved and a more even carrier and gain distribution is obtained. However, due to reduced bandgap of the quaternary InGaAsP p-cladding, an enhanced electron leakage out of the QWs into the p-cladding degrades the laser efficiency and increases the threshold current. Transient time - domain simulations are also performed to determine the small-signal modulation response of the laser promising a simulated high modulation bandwidth suitable for direct-modulation applications.
Place, publisher, year, edition, pages
2004. Vol. 36, no 9, 827-846 p.
Directly modulated lasers; Lateral current injection; Multiple quantum well; Bandwidth; Cladding (coating); Computer simulation; Heterojunctions; Laser beam effects; Particle beam injection; Phase modulation; Quantum well lasers
IdentifiersURN: urn:nbn:se:kth:diva-24235DOI: 10.1023/B:OQEL.0000040062.76050.bfISI: 000223644100005ScopusID: 2-s2.0-4444366097OAI: oai:DiVA.org:kth-24235DiVA: diva2:345848
QC 201008272010-08-272010-08-272010-08-27Bibliographically approved