  We study the characteristics of the quantum state of light produced by a
conditional preparation protocol totally performed in the continuous variable
regime. It relies on conditional measurements on quantum intensity correlated
bright twin beams emitted by a non-degenerate OPO above threshold. Analytical
expressions as well as computer simulations of the selected state properties
and preparation efficiency are developed and show that a sub-Poissonian state
can be produced by this technique. Projection onto a given trigger value is
studied and then extended to a finite band. The continuous variable regime
offers the unique possibility to improve dramatically the preparation
efficiency by choosing multiple selection bands and thus to generate a great
number of sub-Poissonian states in parallel.
