Light-induced specular-reflectivity suppression at a gallium/silica interface.

The reflectivity of a gallium/silica interface formed on an optical flat or at the tip of a cleaved optical fiber can be reduced in a reversible fashion when the interface is excited by a few milliwatts of laser power. This phenomenon occurs at temperatures just below gallium's melting point. We believe that the effect can be attributed to light-induced structuring at the interface.

Femtosecond cubic optical nonlinearity of thin nickel films.

Transient pump-probe measurements of circular anisotropy in nickel films induced by 38-fs optical pulses show an instantaneous response that is related to the optical orientation of the spins of free electrons. Measurements in a sample of variable thickness, performed in both transmission and reflection, revealed that the surface significantly influences the degenerate cubic optical nonlinearity of the nickel films to a depth of approximately 4-5 nm into the bulk.

Cross-wavelength all-optical switching using nonlinearity of liquefying gallium.

The gallium/silica interface optical nonlinearity associated with a light-induced structural phase transition from a-gallium to a more reflective, more metallic phase shows an exceptionally broadband spectral response. It allows 40% deep nanosecond/microsecond cross-wavelength intensity modulation between signals at 1.3 and 1.55aem.