Saturable absorption by carbon nanotubes on silica microtoroids

Tsutaru Kumagai, Naoya Hirota, Katsuya Sato, Koki Namiki, Hideyuki Maki, Takasumi Tanabe

研究成果: Article査読

9 被引用数 (Scopus)

抄録

Saturable absorption is a key technology for shaping the waveform of light such as in passive mode-locking. The combination of high-Q optical microcavities with a saturable absorber allows stable lasing and soliton formation. This work describes saturable absorption by carbon nanotubes (CNTs) on silica microtoroids. CNTs, which are saturable absorbers capable of a fast response time and broadband absorption, were grown on silica microtoroids by chemical vapor deposition (CVD). Raman spectroscopy revealed that the CNTs are in good quality (G/D ratio ∼ 7) and about 1.0 nm in diameter, thus confirming that a sample for use in the telecommunication band can be prepared by CVD. A counter-propagating pump-probe experiment enabled us to investigate the characteristics of CNTs as saturable absorbers while suppressing thermo-optic bistability in a microcavity system. The results revealed a saturable absorption coefficient of 0.042 cm-1, a saturable intensity of 25.9 MW/cm2, and a modulation depth of 28%. This is the first step toward the demonstration of the robust mode-locking in a silica microtoroid consisting of CNTs.

本文言語English
論文番号233104
ジャーナルJournal of Applied Physics
123
23
DOI
出版ステータスPublished - 2018 6 21

ASJC Scopus subject areas

  • 物理学および天文学(全般)

フィンガープリント

「Saturable absorption by carbon nanotubes on silica microtoroids」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル