Surface acoustic wave actuated plasmonic signal amplification in a plasmonic waveguide

Area of Science:

• Photonics
• Materials Science
• Nanotechnology

Background:

• Subwavelength waveguides are crucial for photonic interconnects but face limitations in energy confinement and propagation length.
• Plasmonic waveguide technology requires innovation to overcome diffraction limits and achieve mass-scale applications.
• Existing plasmonic waveguides struggle with insufficient confined energy and short propagation lengths.

Purpose of the Study:

• To propose and demonstrate a novel method for amplifying propagating plasmons using external on-chip acoustic signals.
• To enhance nanoscale confinement in subwavelength waveguides for improved photonic interconnects.
• To overcome the limitations of current plasmonic waveguide technology.

Main Methods:

• Utilizing a gold-silicon dioxide (Au-SiO2) interface on a Lithium Niobate (LN) substrate to excite surface plasmons.
• Applying voltage-varying surface acoustic waves (SAW) to tune plasmonic confinement and modulate intensity.
• Experimentally measuring plasmonic intensity gain under SAW excitation.

Main Results:

• Demonstrated amplification of propagating plasmons through on-chip surface acoustic signals.
• Achieved a plasmonic intensity gain of 1.08 dB.
• Showcased the ability to tune plasmonic confinement and enhance intensity using SAW.

Conclusions:

• Surface acoustic waves offer a viable method to enhance plasmonic intensity and confinement in waveguides.
• This approach addresses key limitations in plasmonic waveguide technology, paving the way for advanced photonic interconnects.
• The proposed method provides a new avenue for reliable on-chip optical waveguides beyond the diffraction limit.