Transfer of orbital angular momentum through sub-wavelength waveguides

Area of Science:

• Photonics
• Optical Communications
• Nanotechnology

Background:

• Optical fiber data capacity is limited by non-linear effects.
• Orbital angular momentum (OAM) offers a new degree of freedom to increase optical communication capacity.

Purpose of the Study:

• To demonstrate the propagation of OAM light in sub-wavelength plasmonic circular waveguides.
• To investigate the propagation loss and bending capabilities of these waveguides for OAM modes.

Main Methods:

• Fabrication of sub-wavelength diameter plasmonic circular waveguides.
• Experimental demonstration of OAM light (topological charge 1 and 2) propagation.
• Measurement of propagation loss and performance in sharp bends.

Main Results:

• Successful propagation of OAM light with topological charge 1 and 2 in sub-wavelength plasmonic waveguides.
• Achieved low propagation loss of 2.73 dB/μm.
• Confirmed maintenance of OAM light in sharp-bended waveguides.

Conclusions:

• Plasmonic waveguides enable OAM light propagation at the sub-wavelength scale with low loss.
• These waveguides maintain OAM integrity even in sharp bends.
• This technology is a potential key component for on-chip optical systems utilizing OAM.