Optically controlled imaging phase mask element.

We demonstrate a new optical element consisting of a phase mask made of a nonlinear material. The element uses the nonlinearity to produce an intensity-dependent lens that controls its imaging properties. We demonstrate this element by optically controlling the imaging of an array produced by a diffractive spot generator in direct contact with a thin semiconductor-doped glass slab. The image at 632.8 nm is controlled by 514.5-nm light from an argon-ion laser.

Nonlinear Christiansen filter.

We demonstrate a nonlinear Christiansen filter in both the steady state and the transient regimes and in both the self- and the cross-modulation modes. Experiments in which a thermal nonlinearity was used agree well with predictions based on a modified scattering theory model.