Mutual mode control of short- and long-range surface plasmons

Area of Science:

• Photonics and Plasmonics
• Nanotechnology
• Optical Integrated Circuits

Background:

• Symmetric metal slab waveguides support both short-range surface plasmon (SRSP) and long-range surface plasmon (LRSP) like modes.
• SRSP modes offer strong field confinement crucial for nano-optical circuits but have limited propagation length.
• A trade-off exists between field confinement and propagation length in SRSP modes.

Purpose of the Study:

• To overcome the confinement-propagation length trade-off in SRSP modes.
• To demonstrate selective excitation of specific surface plasmon modes.
• To achieve mutual mode conversion between SRSP and LRSP modes for nanofocusing.

Main Methods:

• Utilized a symmetric metal slab waveguide structure.
• Investigated selective excitation of SRSP and LRSP like modes.
• Demonstrated mutual mode conversion between the two plasmonic modes.

Main Results:

• Successfully achieved selective excitation of SRSP and LRSP like modes.
• Demonstrated efficient mutual mode conversion between SRSP and LRSP modes.
• Mediated nanofocusing using the LRSP like mode.

Conclusions:

• Selective mode excitation and conversion offer a pathway to manage the trade-off between field confinement and propagation length.
• This approach enables enhanced nanofocusing capabilities in optical integrated circuits.
• The demonstrated techniques hold promise for advanced plasmonic devices.