Compact gradual bends for channel plasmon polaritons

Area of Science:

• Nanophotonics
• Plasmonics
• Optical Engineering

Background:

• Channel plasmon polaritons (CPPs) offer sub-wavelength light confinement.
• Efficient guiding of CPPs around bends is crucial for integrated photonic devices.
• Telecom wavelengths present specific challenges for plasmonic guiding.

Purpose of the Study:

• To design and fabricate compact gradual bends for CPPs.
• To characterize the guiding performance of these bends at telecom wavelengths.
• To quantify the optical losses associated with the bends.

Main Methods:

• Design of gradual S-bends in V-groove waveguides.
• Fabrication of gold V-groove structures.
• Near-field optical imaging to visualize CPP propagation.
• Analysis of intensity profiles to quantify bend loss.

Main Results:

• Successful fabrication of compact S-bends for CPPs.
• High-quality near-field images demonstrating good CPP confinement and guiding.
• Efficient guiding of CPPs around a 5-mum S-bend connecting offset grooves.
• Total bend loss measured at approximately 2.3 dB for wavelengths between 1430-1640 nm.

Conclusions:

• Compact gradual bends are effective for guiding CPPs at telecom wavelengths.
• The fabricated bends exhibit low loss, suitable for integrated plasmonic circuits.
• This work advances the development of on-chip plasmonic components.