Active Mode Switching in Plasmonic Microlasers by Spatial Control of Optical Gain

Area of Science:

• Optoelectronics
• Nanotechnology
• Laser Physics

Background:

• Miniaturized optical sources are crucial for on-chip applications.
• Plasmonic lasers offer potential for advanced spectroscopy and information technology.
• Active wavelength tuning in plasmonic lasers remains an underexplored area.

Purpose of the Study:

• To demonstrate optically controlled wavelength switching in a plasmonic microlaser.
• To explore the potential for facile and active tuning of output wavelengths.
• To enable advanced functionalities in on-chip optical devices.

Main Methods:

• Fabrication of Fabry-Pérot plasmonic cavities with curved block reflectors on a silver surface.
• Deposition of CdSe/CdZnS/ZnS colloidal core/shell/shell nanoplatelets as the gain medium.
• Spatial modulation of the gain profile using structured illumination to control transverse modes.

Main Results:

• Demonstrated optically controlled switching between predefined wavelengths within a single plasmonic microlaser.
• Achieved spatial and energetic separation of transverse modes due to cavity geometry.
• Showcased active selection and switching between four transverse modes by modulating the gain profile.

Conclusions:

• The developed plasmonic microlaser enables optically controlled wavelength switching.
• The device architecture facilitates mode separation and selection for tunable laser output.
• Picosecond switching times are achievable, paving the way for high-speed optical applications.