Near-field optical spectroscopy of excitons in single quantum dots

Toshiharu Saiki, Kenichi Nishi

研究成果: Conference article査読


InGaAs single quantum dot photoluminescence spectra and images are investigated by using a low-temperature near-field optical microscope. By modifying the commonly used near-field apertured probe, a high spatial resolution and high detection efficiency are achieved simultaneously. Local collection of the emission signal through a 500 nm (λ/2) aperture contributes to the single-dot imaging with a λ/6 resolution, which is a significant improvement over the conventional spatially resolved spectroscopy. Tailoring the tapered structure of the near-field probe enables us to obtain the emission spectra of single dots in the weak excitation region, where the carrier injection rate is ∼107 excitons/s per dot. By employing such a technique, we examine the evolution of single-dot emission spectra with excitation intensity. In addition to the ground-state emission, excited-state and biexciton emissions are observed for higher excitation intensities. By a precise investigation of the excitation power dependences of individual dots, two-dimensional identification of their emission origins is obtained for the first time.

ジャーナルProceedings of SPIE - The International Society for Optical Engineering
出版ステータスPublished - 1998
イベントFar- and Near-Field Optics: Physics and Information Processing - San Diego, CA, United States
継続期間: 1998 7月 231998 7月 24

ASJC Scopus subject areas

  • 電子材料、光学材料、および磁性材料
  • 凝縮系物理学
  • コンピュータ サイエンスの応用
  • 応用数学
  • 電子工学および電気工学


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