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

Autor: Liu Xiao-Fei, Lei Fuchuan, Wang Tie-Jun, Long Gui-Lu, Wang Chuan
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Nanophotonics, Vol 8, Iss 1, Pp 127-134 (2018)
Druh dokumentu: article
ISSN: 2192-8606
2192-8614
DOI: 10.1515/nanoph-2018-0130
Popis: 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.
Databáze: Directory of Open Access Journals