Inhomogeneously broadened optical gain spectra of InGaN quantum well laser diodes

Kazunobu Kojima, Mitsuru Funato, Yoichi Kawakami, Harald Braun, Ulrich Schwarz, Shinichi Nagahama, Takashi Mukai

Research output: Contribution to journalConference articlepeer-review

16 Citations (Scopus)


Optical gain of InGaN quantum well laser diodes and its internal field dependences are investigated. Gain spectra are experimentally measured by the Hakki-Paoli method. Inhomogeneous broadening of the gain spectra as well as of the electroluminescence spectra increases with In content of the active layers due to potential fluctuation. From measured carrier decay times and current density, we estimated the carrier density for which modal gain overcomes internal loss. We present gain calculation including quantum confined Stark effect, Coulomb screening and valence band structure simultaneously. Calculated and measured carrier densities are in good agreement. In InGaN quantum well laser diodes working at 470 nm, the quantum confined Stark effect reduces the optical transition probability down to 30% of its value without internal field. (Graph Presented)

Original languageEnglish
Pages (from-to)2126-2128
Number of pages3
JournalPhysica Status Solidi (C) Current Topics in Solid State Physics
Issue number6
Publication statusPublished - 2008 Dec 1
Externally publishedYes
Event7th International Conference of Nitride Semiconductors, ICNS-7 - Las Vegas, NV, United States
Duration: 2007 Sep 162007 Sep 21

ASJC Scopus subject areas

  • Condensed Matter Physics


Dive into the research topics of 'Inhomogeneously broadened optical gain spectra of InGaN quantum well laser diodes'. Together they form a unique fingerprint.

Cite this