Quantum Optical Science and Technology (OQ)

Quantum Optical Science and Technology

Interested audience.This group promotes the acquisition of knowledge about the quantum properties of the electromagnetic field and atom-photon interactions. Experiment, theory and technology relevant for atom trapping, Bose condensation, quantum measurements and quantum information are within the purview of quantum optical science.


OSA Quantum Optical Science and Technology Technical Group 20x20 Talks

Wednesday, 16 September, 18:30 -19:30

Join our technical group at Quantum 2.0 and Frontiers in Optics for this special session, which offers a unique platform for individuals to present their research in a creative and concise fashion that differs from the usual oral or poster session. Selected participants from the technical group showcase their research in a presentation of 20 images. Our presenters will talk along to the images in their presentation as each slide advances automatically after just 20 seconds.

Interested in presenting at the 20x20 Talks? Contact tgactivities@osa.org for details.

Diffraction Induced Entanglement Losses

30 September 2020, 12:00 - 13:00 Eastern Time

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High-dimensional (entangled) quantum states are an important resource to increase the channel capacity and to enhance the security of quantum communication protocols.  The orbital angular momentum (OAM) of photons spans an infinite-dimensional Hilbert space, and it is therefore suitable to encode such high-dimensional quantum states. However, disturbances along the light propagation path can deteriorate the information encoded in OAM photonic states. For example, the turbulence-induced phase distortions lead to crosstalk among different OAM modes, which results in OAM entanglement decay. One of the main differences between diffraction and propagation across turbulence is that, in the former case, the scattering of the wave is deterministic. Thus the quantum state corresponding to a diffracted wave is a pure, infinite-dimensional state of a twisted biphoton, whose entanglement can be quantified by a bona fide entanglement measure such as concurrence.

In this webinar, we use this scenario to illustrate the main causes of OAM entanglement losses. Giacomo Sorelli will present an analytical expression that quantifies diffraction-induced entanglement losses in terms of the mutual overlap between the diffracted images of the optical modes used to encode the entanglement. We then use this formula to investigate the role of the radial structure of the encoding OAM modes in mitigating the phase distortions and consequently the entanglement decay. In particular, we prove that entanglement encoded into Bessel-Gaussian modes experiences reduced losses when compared to that encoded into Laguerre-Gaussian modes. In the second part of the webinar, we will study the entanglement losses induced by angular apertures. Using the uncertainty relation for angular position and angular momentum, we demonstrate that the diffraction-induced entanglement losses are a universal function of the product between the angular uncertainty and the OAM of the encoding modes.

What You Will Learn:

  • The webinar will include pedagogical/introductory parts on photonic orbital angular momentum and the uncertainty relation for angular position and angular momentum, as well as a more technical part on our own method to quantify how the entanglement of spatial modes of light is modified by transmission through diffracting screens.

Who Should Attend:

  • Students and researchers interested in quantum optics with spatial modes of light.

On-Demand Quantum Optical Science and Technology Webinars

You can watch any of the following webinar presentations, which were hosted by the OSA Quantum Optical Science and Technology Technical Group, on-demand.

Graciana Puentes Universidad de Buenos AiresChair
Lee C Bassett University of PennsylvaniaVice Chair
Sara L Mouradian Massachusetts Institute of TechnologyEvents Officer
Mohammad Soltani Raytheon BBN TechnologiesIndustry Liaison
Pablo Bianucci Concordia UniversityWebinar Officer

If you are a member of the Quantum Optical Science and Technology Technical Group and have ideas for activities and initiatives to help engage this community, please share them with the chair, Graciana Puentes.


View OSA Technical Group webinars on-demand at any time or register for any of our upcoming webinars online. Each webinar is an hour long and features a technical presentation on a topic selected by your OSA Technical Groups.