Simultaneous wavelength and orbital angular momentum demultiplexing using tunable MEMS-based Fabry-Perot filter.

Area of Science:

• Optoelectronics
• Optical Communications
• Photonics

Background:

• Increasing demand for higher data rates in optical networks necessitates advanced multiplexing techniques.
• Orbital Angular Momentum (OAM) and Wavelength Division Multiplexing (WDM) are key technologies for enhancing spectral efficiency.

Purpose of the Study:

• To demonstrate simultaneous wavelength and OAM multiplexing/demultiplexing of data streams.
• To introduce a novel on-chip tunable micro-component filter integrated with a spiral phase plate.

Main Methods:

• Utilized a MEMS-based Fabry-Perot filter integrated with a spiral phase plate for OAM state transformation and wavelength selection.
• Experimentally multiplexed two wavelengths, each carrying two channels with zero and non-zero OAMs, creating four independent information channels.
• Evaluated power penalties at the hard-decision forward-error correction (HD-FEC) bit-error-rate (BER) limit of 3.8 × 10^-3 under different modulation schemes and wavelength spacings.

Main Results:

• Achieved simultaneous wavelength and OAM multiplexing with low power penalties (e.g., < 1.45 dB for intensity modulation with 0.8 nm spacing).
• Demonstrated effective data transmission with OAM beams of azimuthal orders 1, 2, and 3.
• Showcased the device's performance at a denser 0.4 nm wavelength grid, with maximum power penalties below 1.15 dB.

Conclusions:

• The proposed on-chip filter offers a practical, integrable, and cost-effective solution for simultaneous OAM transformation and WDM.
• This technology holds significant potential for future high-capacity optical communication systems, particularly for short-range links and optical interconnects.