Quantum measurements of spatial conjugate variables: Displacement and tilt of a Gaussian beam

Vincent Delaubert (1, 2) , Nicolas Treps (1) , Charles C. Harb (2) , Ping Koy Lam (2) , Hans A. Bachor (2)

1 LKB (Jussieu) - Laboratoire Kastler Brossel
2 ACQAO - Arc Centre of Excellence for Quantum-Atom Optics

We consider the problem of measurement of optical transverse profile parameters and their conjugate variable. Using multi-mode analysis, we introduce the concept of detection noise-modes. For Gaussian beams, displacement and tilt are a pair of transverse profile conjugate variables. We experimentally demonstrate their optimal encoding and detection with a spatial homodyning scheme. Using higher order spatial mode squeezing, we show the sub-shot noise measurements for the displacement and tilt of a Gaussian beam.

Mots clés: displacement; tilt; position; momentum; squeezing

Domaines: Physique Quantique [quant-ph]

Vincent Delaubert, Nicolas Treps, Charles C. Harb, Ping Koy Lam, Hans A. Bachor. Quantum measurements of spatial conjugate variables: Displacement and tilt of a Gaussian beam. Optics Letters, 2006, 31, pp.1537. ⟨hal-00016078⟩