Gain lifetime characterization through time-resolved stimulated emission in a whispering-gallery mode microresonator

Nanophotonics

article

Xiao-Fei Liu¹  Fuchuan Lei²  Tie-Jun Wang¹  Gui-Lu Long³  Chuan Wang¹ 

[1] State Key Laboratory of Information Photonics and Optical Communications and School of Science, Beijing University of Posts and Telecommunications;Light-Matter Interactions Unit, Okinawa Institute of Science and Technology Graduate University;State Key Laboratory of Low-dimensional Quantum Physics and Department of Physics, Tsinghua University;Beijing Academy of Quantum Information Sciences;College of Information Science and Technology, Beijing Normal University

关键词: gain lifetime characterization;    whispering-gallery mode;    microcavity;   

DOI  :  10.1515/nanoph-2018-0130

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

The precise measurement of gain lifetime at a specific wavelength holds significant importance for understanding the properties of photonic devices and further improving their performances. Here, we show that the evolution of gains can be well characterized by measuring linewidth changes of an optical mode in a microresonator; this method cannot be achieved using time-resolved photoluminescence (PL) spectroscopy. We use an erbium-doped high-Q whispering-gallery microresonator to show the feasibility of this method. With the increase of time after the pump laser is turned off, the transmission spectrum of a probe signal exhibits transitions from a Lorentz peak to a dip; this indicates a decay of optical gains, and the corresponding lifetime is estimated to be 5.1 ms. Moreover, taper fiber coupling is used to increase the pump and collection efficiency. This method can be extended to other materials and nanostructures.

【 授权许可】

CC BY