Strain-compensated quantum dots emitting at 1.5 micron: Resonant nonlinear optical properties and exciton dynamics

Junko Ishi-Hayase, Kouichi Akahane, Naokatsu Yamamoto, Mamiko Kujiraoka, Kazuhiro Ema, Masahide Sasaki

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The population and coherent dynamics of excitons in InAs quantum dots were investigated using transient pump-probe and four-wave mixing spectroscopies in the telecommunications wavelength range. The sample was fabricated on an InP(311)B substrate using strain compensation to control the emission wavelength. This technique also enabled us to stack over a hundred QD layers, which resulted in a significant enhancement of nonlinear signals. By controlling the polarization directions of incident pulses, we precisely estimated the radiative and non-radiative lifetimes, the transition dipole moment, and the dephasing time while taking into account their anisotropic properties. The measured radiative lifetime and dephasing time shows large anisotropies with respect to the crystal axes, which results from the anisotropic nature of the transition dipole moment. The anisotropy is larger than that for InAs quantum dots on a GaAs(100) substrate, which seems to reflect a lack of symmetry on an (311)B substrate. A quantitative comparison of these anisotropies demonstrates that non-radiative population relaxation and pure dephasing are quite small in our QDs.

Original languageEnglish
Title of host publicationNanophotonics for Communication
Subtitle of host publicationMaterials, Devices, and Systems IV
Publication statusPublished - 2007
Externally publishedYes
EventNanophotonics for Communication: Materials, Devices, and Systems IV - Boston, MA, United States
Duration: 2007 Sept 102007 Sept 11

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherNanophotonics for Communication: Materials, Devices, and Systems IV
Country/TerritoryUnited States
CityBoston, MA


  • Quantum dot
  • Strain compensation
  • Transient nonlinear spectroscopy

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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