All-plasmonic switching based on thermal nonlinearity in a polymer plasmonic microring resonator

Area of Science:

• Photonics
• Materials Science
• Nonlinear Optics

Background:

• Plasmonic nanostructures offer unique light-matter interactions.
• Thermal nonlinear effects are crucial for all-optical switching applications.
• Hybrid plasmonic waveguides combine metal and dielectric materials for enhanced properties.

Purpose of the Study:

• Investigate thermal nonlinear effects in a hybrid gold/silica/SU-8 plasmonic microring resonator.
• Quantify the thermo-optic shift and compare it to dielectric resonators.
• Demonstrate all-plasmonic nonlinear switching using this hybrid structure.

Main Methods:

• Fabrication of a hybrid Au/SiO(2)/SU-8 plasmonic microring resonator.
• Experimental measurement of resonance shifts under varying optical power.
• In-plane pump-and-probe measurements to assess switching performance.

Main Results:

• Observed a large, intensity-dependent thermo-optic shift due to ohmic loss in the gold layer.
• Achieved a resonance shift 30 times greater than in a comparable SU-8 dielectric microring.
• Demonstrated all-plasmonic nonlinear switching with a 4 dB on-off contrast at 50 mW input power.

Conclusions:

• Hybrid plasmonic microring resonators exhibit significant thermal nonlinearities.
• The enhanced thermo-optic effect enables efficient all-plasmonic nonlinear switching.
• This technology holds promise for developing advanced optical switching devices.