Author: Carlos Andres Sevilla Gutierrez

DIRECT OBSERVATION OF ORBITAL ANGULAR MOMENTUM CONSERVATION IN COLLINEAR TYPE-I SPDC

Carlos Andres Sevilla Gutierrez (2018)

"We implement a direct measurement of the spatial modes distribution generated in a collinear type I spontaneous parametric down-conversion (SPDC) process using a triggered intensified CCD camera. This type of experiments have been realized previously. However in those cases the measurement was an indirect one, where both photons were collected into one-pixel detectors. In this thesis, to the best or our knowledge, it is the first time that a direct two dimensional measurement of the spatial modes distribution is made. These are well described by Laguerre-Gaussian modes. In our experiments we could observe up to mode l=+/-10. By exploiting the capabilities of an ICCD camera, it is possible to visualize the orbital angular momentum (OAM) conservation of the unprocessed SPDC bi-photon state. This is performed by observing the diffraction pattern by a triangular aperture. We show the results using this method for modes l=+/-1,+/-2. This conservation of OAM leads to entanglement in OAM, since one photon carries the anti-correlated topological charge with respect to the other one. Therefore, they are conditioned to the state of the other photon."

Master thesis

OAM Conservation SPDC Laguerre-Gauss Quantum Entanglement CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA FÍSICA TEÓRICA TEORÍA CUÁNTICA DE CAMPOS TEORÍA CUÁNTICA DE CAMPOS

DIRECT OBSERVATION OF CONSERVATION OF OAM IN COLLINEAR TYPE-I SPDC

Zeferino Ibarra Carlos Andres Sevilla Gutierrez ROBERTO RAMIREZ ALARCON (2018)

"Here we implement a direct measurement of the Spatial modes distribution carrying Orbital Angular Momentum (OAM) generated in collinear type I SPDC, by using a triggered ICCD camera. Modes up to l = 10 were observed, and the probability amplitude of generation of each mode is reported. We also present a method to observe the topological charge of these modes, which we used for the modes l = 1 and l = 2, proving conservation of OAM."

Conference poster

Mecánica cuántica Óptica cuántica Fotónica SPDC CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA QUÍMICA FÍSICA TEORÍA CUÁNTICA TEORÍA CUÁNTICA