Heidelberg 2015 – wissenschaftliches Programm
Q 1.4: Vortrag
Montag, 23. März 2015, 12:15–12:30, C/HSO
Noise in the Beam Width of Spatial Optical Modes — •Vanessa Chille1,2,4, Peter Banzer1,2,3, Andrea Aiello1,2, Gerd Leuchs1,2,3, Christoph Marquardt1,2, Nicolas Treps4, and Claude Fabre4 — 1Max Planck Institute for the Science of Light, Guenther-Scharowsky-Str. 1/Bldg. 24, D-91058 Erlangen, Germany — 2Institute of Optics, Information and Photonics, University of Erlangen-Nuremberg, Staudtstr. 7/B2, D-91058 Erlangen, Germany — 3Department of Physics, University of Ottawa, 25 Templeton, Ottawa, Ontario, K1N 6N5 Canada — 4Laboratoire Kastler Brossel, Sorbonne Université - UPMC, ENS, Collège de France, CNRS; 4 place Jussieu, 75252 Paris, France
Fundamental limits in imaging and beam focusing originate from the spatial distribution of quantum noise. Here we investigate quantum fluctuations in the beam width of transverse optical modes. We start by defining a quantum operator measuring the beam width and study its characteristics. An eigenmode is derived and the canonically conjugate variable of the beam width is determined for a fundamental Gaussian mode. For the very common case of single mode states, we present investigations on the noise of the beam width for coherent and Fock states when the spatial modes represents Hermite-Gauss, Laguerre-Gauss and flattened Gaussian beams. For multimode states with small quantum fluctuations, as for instance in the case of coherent states, the noise of the beam width can be attributed to one particular spatial mode. We give explicit examples.