Polymer dispersed liquid crystal-mediated active plasmonic mode with microsecond response time.

Area of Science:

• Nanophotonics
• Plasmonics
• Liquid Crystal Technology

Background:

• Active plasmonics and liquid crystals (LC) are crucial in nanophotonics.
• Existing devices face limitations in response time and figure of merit (FoM).

Purpose of the Study:

• To propose and demonstrate a fast-response active plasmonic device.
• To enhance device performance through the interplay of plasmonic spectrum and Fabry-Perot (FP) modes.

Main Methods:

• Excitation of plasmonic spectrum in gold nanoparticle (NP) islands.
• Excitation of FP modes within an LC microcavity.
• Utilizing polymer-dispersed LC (PDLC) with a mesogenic monomer for reduced response times.

Main Results:

• Hybrid modes (HMs) formed by FP mode splitting of the NP extinction spectrum.
• Enhanced extinction coefficient due to multiple reflections within the cavity.
• A 45-fold increase in FoM achieved by electric field tuning of HMs.
• Response times reduced to the microsecond range with PDLC, maintaining transparency.

Conclusions:

• The proposed device offers significant improvements in performance and speed for active plasmonics.
• The integration of plasmonic NPs and LC microcavities provides a viable pathway for advanced nanophotonic devices.
• The use of PDLC is key to achieving fast optical switching in the microsecond regime.