Reconstruction of blurred images via controlled spatial-solitons formation

Summary form only given. Quadratic non-linear interaction is known to support the process of spatial soliton formation. A very simple set-up consists of a single pass, single crystal, quantum noise optical parametric amplifier (OPA) pumped by a focussed beam. The diffraction-free propagation achieved in the solitary-wave regime implies that the beam-waist plane of the pump beam can arbitrarily move inside the crystal without any relevant change in the size of the mutually trapped pump, signal and idler beams at the crystal output face. We present a very useful application of this property to the reconstruction of digital images. The experimental set-up is based on a 30 mm temperature tuned lithium triborate (LBO) crystal, operated in noncritical type I phase matching and pumped by a 15 ps, 527 nm pulse from an amplified frequency doubled Nd:glass laser. We set the crystal temperature to 107/spl deg/C to obtain generation at 1.8 /spl mu/m (idler) and 0.75 /spl mu/m (signal), ensuring minimum group velocity mismatch among interacting pulses.