High-resolution optical orbital angular momentum sorter based on Archimedean spiral mapping

Area of Science:

• Optics and Photonics
• Transformation Optics
• Conformal Mapping

Background:

• Orbital Angular Momentum (OAM) multiplexing is crucial for high-capacity optical communication.
• Efficient sorting of OAM modes is a key challenge in OAM-based systems.
• Existing methods for OAM mode sorting often lack versatility and efficiency.

Purpose of the Study:

• To propose a generalized spiral transformation scheme adaptable to various spiral types.
• To demonstrate the application of this scheme for high-resolution optical OAM mode sorting.
• To evaluate the efficiency and crosstalk performance of the proposed method.

Main Methods:

• Developed a generalized spiral transformation adaptable to Archimedean and Fermat spirals.
• Utilized the equidistant feature of Archimedean spiral mapping for OAM mode sorting.
• Conducted experimental validation of the proposed optical transformation scheme.

Main Results:

• Achieved 90% efficiency in sorting optical orbital angular momentum (OAM) modes.
• Demonstrated a crosstalk of -8.78 dB, sufficient for separating adjacent OAM modes.
• The generalized scheme proved versatile and effective for high-resolution OAM mode sorting.

Conclusions:

• The proposed generalized spiral transformation scheme offers a versatile approach for optical applications.
• The Archimedean spiral mapping is effective for high-resolution OAM mode sorting.
• This technique has potential applications in optical transformation and conformal mapping.