1.3 Micron Plasmonic Lasers on Single Crystalline Epitaxial Silver Film
Chien-Ju Lee1*, Han Yeh1, Ping-Hsiang Su2, Yutsung Tsai2, Tsing-Hua Her3, Yen-Chun Chen1, Chun-Yuan Wang4, Jer-Shing Huang5, Shangir Gwo4, Chih-Kang Shih2, Wen-Hao Chang1
1Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
2Department of Physics, The University of Texas at Austin, Austin, Texas, USA
3Department of Physics and Optical Science, The University of North Caroline at Charlotte, Charlotte, North Caroline, USA
4Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
5Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan
* presenting author:Chien-Ju Lee, email:Chienju1016@gmail.com
Reducing the optical mode size and physical dimension of semiconductor lasers holds the key to develop smaller and faster coherent light sources, and to achieve the goal of integrated photonic and plasmonic circuits. Here, we report the first demonstration of plasmonic lasers at telecom wavelength (~1.3 μm) using top-down fabricated semiconductor waveguides on single-crystalline epitaxially grown Ag film. The role of the Ag film thickness, which plays an important role in preventing radiation leakage into the substrate at telecom wavelength, is investigated systematically. Continuous-wave operation of plasmonic lasers with threshold as low as 0.2 MW/cm2 at cryogenic temperatures can be achieved on a 150-nm thick Ag film. Our plasmonic lasers preferentially lase through higher-order surface-plasmon-polariton mode, which exhibits higher mode confinement factor, lower propagation loss and better field-gain overlap. Temperature dependent measurement shows that our devices can sustain plasmonic lasing up to 200 K under pulse excitations. The 1.3 μm plasmonic lasers on large-area epitaxial Ag film open up a scalable platform for on-chip integrations of plasmonics and optoelectronics for future telecom applications.

Keywords: plasmonics, plasmonic lasers