Details

Autor(en) / Beteiligte

• Lim, Wen Xiang
• Manjappa, Manukumara
• Srivastava, Yogesh Kumar
• Cong, Longqing
• Kumar, Abhishek
• MacDonald, Kevin F.
• Singh, Ranjan

Titel

Ultrafast All‐Optical Switching of Germanium‐Based Flexible Metaphotonic Devices

Ist Teil von

• Advanced materials (Weinheim), 2018-03, Vol.30 (9), p.n/a

Ort / Verlag

Germany: Wiley Subscription Services, Inc

Erscheinungsjahr

2018

Quelle

Wiley Online Library

Beschreibungen/Notizen

• Incorporating semiconductors as active media into metamaterials offers opportunities for a wide range of dynamically switchable/tunable, technologically relevant optical functionalities enabled by strong, resonant light–matter interactions within the semiconductor. Here, a germanium‐thin‐film‐based flexible metaphotonic device for ultrafast optical switching of terahertz radiation is experimentally demonstrated. A resonant transmission modulation depth of 90% is achieved, with an ultrafast full recovery time of 17 ps. An observed sub‐picosecond decay constant of 670 fs is attributed to the presence of trap‐assisted recombination sites in the thermally evaporated germanium film. Ultrafast all‐optical switching of a germanium‐based flexible metaphotonic device demonstrates ultrafast modulation of Fano and dipole resonances with a full recovery time of 17 ps. Relaxation of photoexcited carriers occurs with a sub‐picosecond time constant of 670 fs, attributed to surface defects in thermally evaporated germanium on the ultrathin flexible metadevice.