US Patent 9658510 Devices, systems and methods for ultrafast optical applications

An optical device capable of an ultrafast and large change of its reflection or absorption coefficient upon being excited by an ultrafast optical pulse with wavelength in the visible, near-infrared, or infrared spectral regions. The optical device includes, in sequential order, a first thick metallic layer, a first dielectric layer, a second thin metallic layer, and a second dielectric layer. The optical device acts as a nonlinear mirror that presents a large reflectance at low irradiance and a low reflectance at large irradiance. The optical device can further act as a nonlinear mirror that presents a linear and nonlinear reflectance with a large angular bandwidth.