Skip to main content

Home

HomeEventsHigh-Dimensional Orbital Angular Momentum Entanglement in Optical Fibers

Events - Event View

This is the "Event Detail" view, showing all available information for this event. If the event has passed, click the "Event Report" icon to read a report and view photos that were uploaded.
High-Dimensional Orbital Angular Momentum Entanglement in Optical Fibers

Date and Time

Wednesday, October 22, 2025, 6:00 PM until 8:00 PM

Location

Boston University Photonics Center
8 St Marys St
Boston, MA  02215
USA

Event Contact(s)

Kaitlin Mason

Category

Monthly Talk

Registration Info

Registration is required
Payment in Full In Advance Or At Event

About this event

Abstract
Quantum states encoded in high-dimensional Hilbert spaces provide advantages over conventional two-level systems, including increased information capacity per photon, enhanced robustness against noise, and stronger violations of local realism in entanglement tests. The photon’s orbital angular momentum (OAM), with its unbounded integer values, is a natural platform for such encoding. Traditionally, OAM states are generated through spontaneous parametric downconversion (SPDC) in bulk crystals, but the resulting free-space modes are not directly compatible with optical fiber networks and typically require lossy post-selection to equalize mode-dependent emission amplitudes.

This work investigates the generation of high-dimensional OAM states in multimode ring-core fibers (RCFs) using intermodal spontaneous four-wave mixing (SFWM). The stability and scalability of OAM propagation in RCFs are analyzed, followed by the principles of SFWM between guided modes. A versatile inverse-design algorithm enables complete control over the amplitude and phase of the pump field, supporting arbitrary OAM superpositions and processing of the generated states. The spectral correlations of the emitted photon pairs, described by the joint spectral amplitude (JSA), are shown to depend on mode selection and can be tuned nondestructively from correlated to uncorrelated to anti-correlated distributions. High single-photon performance is demonstrated with heralded second-order correlations below 0.005 and coincidence-to-accidental ratios above 4000, which to the best of current knowledge represent the highest values reported for fiber-based systems using avalanche photodetectors. Furthermore, through enforcement of JSA overlap, OAM correlations spanning 15 transverse dimensions in fiber are identified, each maintaining high single-photon performance. This result establishes a foundation for fiber-based high-dimensional transverse-mode entanglement and outlines a scalable pathway toward quantum networks.


 





Speakers Bio
Daniel Shahar is a sixth-year Ph.D. candidate in the High-Dimensional Photonics Laboratory at Boston University, where he conducts research under the supervision of Dr. Siddharth Ramachandran (https://sites.bu.edu/ramachandranlab/). He was awarded the NSF Graduate Research Fellowship in 2022. In 2020, he earned B.S. degrees in Physics, Mathematics, and Electrical Engineering from the University of Florida.

Number of People Who Will Attend

Any Non-Member *
* This can be your primary registrant type. Only one primary registrant type is allowed per registration.
Register Now
Activities/Items (Click the down-arrow to view details)
High-Dimensional Orbital Angular Momentum Entanglement in Optical Fibers
Dinner & Networking