Optical mode conversion via spatiotemporally modulated atomic susceptibility.

Area of Science:

• Quantum optics
• Atomic physics
• Information science

Background:

• Light is a key medium for classical and quantum information.
• Space-division multiplexing with Laguerre-Gaussian modes increases data rates.
• High-dimensional encoding requires efficient photonic manipulation devices.

Purpose of the Study:

• To demonstrate controlling optical susceptibility for light manipulation.
• To achieve efficient photonic mode conversion using atomic samples.
• To explore applications in quantum information and communication.

Main Methods:

• Utilizing an atomic sample to control optical susceptibility.
• Spatiotemporal modulation of atomic susceptibility with a Stark-shifting beam.
• Implementing mode conversion within a twisted optical cavity.

Main Results:

• Achieved high-efficiency photonic mode conversion between Laguerre-Gaussian modes (l=3 to l=0).
• Conversion efficiency saturates near unity with increasing atom number and modulation intensity.
• Demonstrated a novel mode-coupling optic based on modulated atomic susceptibility.

Conclusions:

• Controlling atomic optical susceptibility is a powerful tool for manipulating light.
• The demonstrated technique offers high efficiency for photonic mode conversion.
• Potential applications include topological state preparation, quantum communication, and flexible tabletop devices.