New Tools for Photonic Entanglement

Olga V. Minaeva, Cristian Bonato, Bahaa E. A. Saleh +1 more

Here we introduce a new quantum-optical tool for dispersion management. This technique allows for simultaneous observation of quantum cancellation of odd-order and even-order dispersion using frequency-anticorrelated entangled photons.

Xiongfeng Ma

Panagiotis Vergyris

Thiago Guerreiro

Quantum mechanics not only revolutionized physics, but also provided an important tool allowing the development of unprecedented technology in the past century. Today, the quantum revolution continues to shape the development of new technologies through the fields of quantum information and communication. This thesis deals with the generation, manipulation and detection of quantum information using single photons. Creating single photons with precision, interacting individual photons and generating quantum entanglement are some of the questions we will deal with in detail.

Juan P. Torres, Gabriel Molina‐Terriza, Lluís Torner

Twisted light, or light with orbital angular momentum (OAM), plays an emerging role in both classical and quantum science, with important applications in areas as diverse as biophotonics, micromachines, spintronics, or quantum information. It offers fascinating opportunities for exploring new fundamental ideas in physics, as well as for being used as a tool for practical applications. One important point is to determine how to generate single photons, and two-photon states, with an appropriate OAM content. Here we describe the paraxial orbital angular momentum of entangled photon pairs generated by spontaneous parametric down-conversion (SPDC) in different non-collinear geometries. These geometries introduce a variety of new features. In particular, we find the OAM of entangled pairs generated in purely transverse-emitting configurations, where the entangled photons counter-propagate perpendicularly to the direction of propagation of the pump beam. The spatial walk-off of all interacting waves in the parametric process also determines the OAM content of the down-converted photons, and here its influence is also revealed.