Ultra-short pulse generation by a topological insulator based saturable absorber
Abstract
Under strong laser radiation, a Dirac material, the topological insulator (TI) Bi2Te3, exhibits an optical transmittance increase as a result of saturable absorption. Based on an open-aperture Z-scan measurement at 1550 nm, we clearly show that the TI, Bi2Te3 under our investigation, is indeed a very-high-modulation-depth (up to 95%) saturable absorber. Furthermore, a TI based saturable absorber device was fabricated and used as a passive mode locker for ultrafast pulse formation at the telecommunication band. This contribution unambiguously shows that apart from its fantastic electronic property, a TI (Bi2Te3) may also possess attractive optoelectronic property for ultrafast photonics.
- Publication:
-
Applied Physics Letters
- Pub Date:
- November 2012
- DOI:
- 10.1063/1.4767919
- Bibcode:
- 2012ApPhL.101u1106Z
- Keywords:
-
- bismuth compounds;
- optical pulse generation;
- optical saturable absorption;
- topological insulators;
- 42.65.Re;
- 42.50.Gy;
- Ultrafast processes;
- optical pulse generation and pulse compression;
- Effects of atomic coherence on propagation absorption and amplification of light;
- electromagnetically induced transparency and absorption