  Using continuous wave superposition of spatial modes, we demonstrate
experimentally displacement measurement of a light beam below the standard
quantum limit. Multimode squeezed light is obtained by mixing a vacuum squeezed
beam and a coherent beam that are spatially orthogonal. Although the resultant
beam is not squeezed, it is shown to have strong internal spatial correlations.
We show that the position of such a light beam can be measured using a split
detector with an increased precision compared to a classical beam. This method
can be used to improve the sensitivity of small displacement measurements.
