A 1.6 µm dual-channel cylindrical vector laser enabling multi-state shift keying

Area of Science:

• Optics and Photonics
• Laser Physics
• Quantum Information

Background:

• Cylindrical vector (CV) beams possess unique polarization properties with applications in optical trapping, microscopy, and information processing.
• Generating multiple CV beams with distinct polarization orders simultaneously presents a significant challenge in laser design.

Purpose of the Study:

• To demonstrate a novel dual-channel Er:YAG laser capable of simultaneously generating two distinct cylindrical vector (CV) beams.
• To investigate the potential of this dual-channel CV laser for free-space optical data transmission.

Main Methods:

• A 1645 nm end-pumped dual-channel Er:YAG laser was designed with a two-arm structure.
• Each arm incorporated a q-plate (QP) to induce intra-cavity spin-orbital angular momentum conversion, generating different CV modes.
• Acousto-optic modulators were used to encode data onto the output CV beams for transmission experiments.

Main Results:

• The laser successfully generated two simultaneous CV beams with different polarization orders.
• High power stability and polarization mode purity were experimentally verified.
• Successful free-space data transmission was achieved by encoding digital symbols onto the dual CV modes.

Conclusions:

• The developed dual-channel Er:YAG vector laser provides a robust platform for generating multiple CV beams.
• The system demonstrates significant potential for advanced optical communication systems and free-space data transmission applications.