title: A quantum laser pointer.
abstract: The measurement sensitivity of the pointing direction of a laser beam is ultimately limited by the quantum nature of light. To reduce this limit, we have experimentally produced a quantum laser pointer, a beam of light whose direction is measured with a precision greater than that possible for a usual laser beam. The laser pointer is generated by combining three different beams in three orthogonal transverse modes, two of them in a squeezed-vacuum state and one in an intense coherent field. The result provides a demonstration of multichannel spatial squeezing, along with its application to the improvement of beam positioning sensitivity and, more generally, to imaging.
authors.affiliation: Australian Research Council Centre of Excellence for Quantum-Atom Optics, the Australian National University, Canberra ACT 0200, Australia. nicolas.treps@spectro.jussieu.fr
authors.forename: Nicolas
authors.initials: N
authors.lastname: Treps
authors.forename: Nicolai
authors.initials: N
authors.lastname: Grosse
authors.forename: Warwick P
authors.initials: WP
authors.lastname: Bowen
authors.forename: Claude
authors.initials: C
authors.lastname: Fabre
authors.forename: Hans-A
authors.initials: HA
authors.lastname: Bachor
authors.forename: Ping Koy
authors.initials: PK
authors.lastname: Lam