%0 Journal Article
%A Pham, Van Hoi
%A Bui, Huy
%A Pham, Thanh Son
%A Nguyen, The Anh
%A Nguyen, Thuy Van
%A Le, Huu Thang
%A Bui, Trung Ninh
%A Nguyen, Van Phu
%A Roberto, Coisson
%D 2013
%F SisLab:2098
%J J. Opt. Soc. Am. B
%N 6
%P 1586-1589
%T Control of whispering-gallery-mode spectrum from  erbium-doped silica microsphere lasers
%U https://eprints.uet.vnu.edu.vn/eprints/id/eprint/2098/
%V 30
%X High-power whispering-gallery modes (WGMs) emitted from microcavity lasers have attracted attention for many  applications, such as optical signal processing, spectroscopy, optical sensors, and large-bandwidth optical com-  munications. In this paper, we present a simple approach for controlling the outputWGMs of erbium-doped silica  microsphere lasers. With the presented scheme, accurate adjustment of the coupling gap between the collection  fiber taper and the spherical surface allows us to select different single modes of the microsphere laser or different  multimode configurations (also functions of the waist diameter of taper and the Er-doped concentration). The  nonlinear frequency shift of the microsphere cavity as a function of intracavity power has also been studied.  The high intensity and high sidemode suppression ratio of the obtained singleWGMare suitable for spectroscopy,  optical sensors, and communications. © 2013 Optical Society of America