A method is proposed for the experimental determination of the amplitude and phase structure of a quasirnonochromatic wave field in a plane normal to its propagation direction. The wave field may represent either a scalar electromagnetic (EM) field or the quantum mechanical (QM) wave function of a

Phase-space tomography is experimentally demonstrated for the determination of the spatially varying amplitude and phase of a quasi-monochromatic optical field by measurements of intensity only. Both fully and partially coherent sources are characterized. The method, which makes use of the fractional-order Fourier transform, also yields the Wigner distribution of the field and works in one or two dimensions.

We propose and demonstrate a method for determining the two-time photon-number correlations of an optical field on ultrafast time scales. The method, which uses dual-pulse, phase-averaged, balanced-homodyne detection, is sensitive at the single-photon level and can have a quantum efficiency approaching 100%. Using this method we have determined the two-time, photon-number correlations on subpicosecond time scales of emission from a semiconductor optical amplifier. ͓S1050-2947͑97͒51003-1͔

We propose schemes for measuring the joint quantum state of a two-mode optical field using balanced homodyne detection, thereby generalizing earlier single-mode schemes. We distinguish between two casesthe case where the two modes are spatially separable and the case where they are nonseparable. For each case we present a generalization of the direct sampling method of state reconstruction and point out that its advantages over inverse Radon methods are even greater here than in the single-mode case. In the case of two modes that cannot be separated we propose a scheme in which a single balanced homodyne detector is used for data collection. ͓S1050-2947͑96͒00309-5͔

No abstract