Mode-group selective photonic lanterns for multiplexing multi-order orbital angular momentum modes.

Area of Science:

• Optoelectronics
• Photonics
• Optical Communications

Background:

• Orbital Angular Momentum (OAM) multiplexing is crucial for enhancing space division multiplexing (SDM) capacity.
• Limited research exists on multiplexing multi-order OAM modes using photonic lanterns, hindering SDM system development.

Purpose of the Study:

• To propose and demonstrate an Annular Multicore Photonic Lantern (AMCPL) capable of multiplexing multiple OAM mode groups.
• To investigate the impact of multicore arrangements on crosstalk (XT) between OAM modes.
• To provide a quantum interpretation of supermode evolution in the AMCPL.

Main Methods:

• Design and simulation of an AMCPL with various multicore arrangements.
• Optimization of the multicore arrangement to minimize crosstalk between OAM modes.
• Analysis of mode conversion efficiency and crosstalk performance across a wavelength range (1300-1600 nm).
• Quantum mechanical analysis of supermode evolution.

Main Results:

• An optimized inverted multicore arrangement for the OAM AMCPL was achieved, balancing crosstalk for high-order OAM modes (|l|=2 to 5).
• The highest crosstalk between target OAM mode groups was below -27.20 dB.
• Mode conversion efficiencies for all target OAM mode groups exceeded 99.5%.
• A novel quantum interpretation of supermode evolution was presented.

Conclusions:

• The proposed OAM AMCPL effectively multiplexes high-order OAM modes with low crosstalk and high efficiency.
• The findings pave the way for advanced OAM-based SDM systems.
• The quantum interpretation offers new insights into light propagation in multicore photonic lanterns.