Multimode squeezing of transverse modes with a self-imaging optical parametric oscillator

We present here an experimental demonstration of the direct production of a multimode non-classical state, using an OPO in a degenerate cavity. The cavity is self-imaging, which means that theoretically all transverse modes of a given wavelength can be resonant. In particular, any image imprinted on a laser beam can be transmitted through it. This cavity consists in a plane mirror, a lens, and a spherical mirror.