Wavelength-selective orbital-angular-momentum beam generation using MEMS tunable Fabry-Perot filter

Area of Science:

• Photonics
• Optical Communications
• Microelectromechanical Systems

Background:

• Orbital angular momentum (OAM) multiplexing offers increased data capacity in optical communications.
• Current OAM systems often lack wavelength selectivity and miniaturization.
• Integrated photonic devices are crucial for next-generation communication systems.

Purpose of the Study:

• To demonstrate an on-chip device for wavelength-selective generation of vortex beams.
• To develop a compact, robust, and cost-effective solution for simultaneous OAM and wavelength-division multiplexed optical communications.

Main Methods:

• Integration of a spiral phase plate onto a microelectromechanical system (MEMS) tunable filter.
• Operation within the 1550 nm wavelength regime.
• Experimental characterization of OAM spectra for azimuthal orders 1, 2, and 3.

Main Results:

• The device functions simultaneously in both wavelength and orbital-angular-momentum (OAM) domains.
• Achieved OAM state purity greater than 92% for azimuthal orders 1, 2, and 3.
• Demonstrated functionality across a wavelength range exceeding 30 nm.

Conclusions:

• The vortex MEMS filter is a promising solution for simultaneous OAM- and wavelength-division multiplexed optical communications.
• The device offers a compact, robust, and cost-effective approach to advanced optical networking.
• High OAM state purity over a broad wavelength range validates the technology.