title: Dual-wavelength single-frequency laser emission in asymmetric coupled microdisks.
abstract: The gain and loss in a microcavity laser play an important role for the modulation of laser spectrum. We show that dual-wavelength single mode lasing can be achieved in an asymmetric coupled system consisted of two size-mismatched microdisks. The amount of eigenmodes in this coupled-microdisk system is reduced relying on the Vernier effect. Then a single mode is selected to lase by controlling the gain branching in the supermodes. The supermodes are formed by the coupling between different transverse whispering-gallery modes (WGMs). When the gain/loss status between the two mirodisks is changed through selectively pumping process, the modulated gain branching for various supermodes leads to the switchable single-frequency laser emission. The results obtained in this work will provide the further understand for the spectral modulation mechanism in the coupled microcavity laser system.
authors.affiliation: Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Key Lab for Micro and Nanophotonic Structures (Ministry of Education), and Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Haotian
authors.initials: H
authors.lastname: Wang
authors.affiliation: Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Key Lab for Micro and Nanophotonic Structures (Ministry of Education), and Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Liu
authors.affiliation: Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Key Lab for Micro and Nanophotonic Structures (Ministry of Education), and Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.affiliation: Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Key Lab for Micro and Nanophotonic Structures (Ministry of Education), and Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Deyuan
authors.initials: D
authors.lastname: Shen
authors.affiliation: Shanghai Ultra-precision Optical Manufacturing Engineering Research Center, Key Lab for Micro and Nanophotonic Structures (Ministry of Education), and Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Wu