Temperature sensitivity of the threshold current of long-wavelength InGaAs/GaAs VCSELs with large gain-cavity detuning
2004 (English)In: IEEE Journal of Quantum Electronics, ISSN 0018-9197, Vol. 40, no 5, 453-462 p.Article in journal (Refereed) Published
Record-long emission wavelengths up to 1.3 mhaverecently been demonstrated from highly strained InGaAs–GaAsdouble-quantum-well (DQW) vertical-cavity surface-emittinglasers (VCSELs). The operation of InGaAs VCSELs at suchlong wavelengths has relied on a large detuning between thespectral positions of QW gain maximum and cavity resonance.This detuning also affects the high-temperature performance andtemperature sensitivity of such devices. In this paper, we presentand evaluate the threshold current–temperature characteristicof such lasers in relation to the gain-cavity detuning at roomtemperature (RT). For a near-zero gain peak offset from theemission wavelength at RT, the minimum threshold current isfound at the temperature where the gain peak wavelength and thecavity resonance are approximately aligned. This is well in linewith a common design rule for GaAs-based VCSELs. However,we show that this design rule fails in the case of larger gain-cavitymisalignment at RT. Instead, a minimum threshold current is obtainedconsiderably below the temperature of zero gain offset. Wepropose a conceptual model that relates the gain-cavity detuning atRT to the temperature sensitivity of the active region performance,which qualitatively describes the threshold current–temperaturecharacteristic typical of VCSELs. The results demonstrate theimportance of improving the temperature characteristic of theactive region in order to reduce the high temperature sensitivityof devices with large detuning.
Place, publisher, year, edition, pages
2004. Vol. 40, no 5, 453-462 p.
Gain offset, InGaAs–GaAs, long-wavelength, temperature sensitivity, vertical-cavity surface-emitting laser (VCSEL)
IdentifiersURN: urn:nbn:se:kth:diva-5288DOI: 10.1109/JQE.2004.826421ISI: 000221090900003ScopusID: 2-s2.0-2442459997OAI: oai:DiVA.org:kth-5288DiVA: diva2:8294
QC 201010012005-06-072005-06-072010-10-01Bibliographically approved