Storage of orbital angular momentum information into acoustic waves

• Applicant: Professorin Dr. Birgit Stiller
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 553206021

Optical information has many degrees of freedom: amplitude, phase, frequency, polarization, orbital angular momentum, coherence, temporal dynamics and more. In optical fibers and optical waveguides, the variety of different guided spatial mode shapes come as addition. To process optical information, it is beneficial to be able to use all-optical techniques because other approaches such as electro-optic control limit the bandwidth and are constraint in terms of speed. Manipulation of optical information includes - but is not limited to - amplification, frequency conversion, delaying and routing of optical signals. One approach to process optical information with control light was recently experimentally demonstrated via interaction with acoustic waves. The nonlinear optical effect of stimulated Brillouin-Mandelstam scattering links optical and acoustic waves and can be used to store optical information into sound waves. The concept was shown to preserve amplitude and phase, the frequency and a temporal series of pulses. Over the past decade, there has been extensive utilization of spatial channels (polarization states and optical modes) to enhance optical communication capacity and this technology is becoming a promising transmission method in data centers and quantum communication systems. However, the storage and retrieval of polarization states and spatial information have not yet been carried out so far. In this project, we aim to store polarization, orbital angular momentum and spatial information into traveling acoustic waves. The concept is to be demonstrated in chiral photonic crystal fibers which stably guide circular polarization as well as orbital angular momentum modes.

• DFG Programme: Research Grants
• Co-Investigator: Dr. Xinglin Zeng