Nonlinear-optical energy regulation by nonlinear refraction and absorption in silicon

We demonstrate a new silicon picosecond nonlinear-optical energy regulator for 1-microm radiation. The device has a high transmission for low input energies and a low transmission for high input energies and clamps the output at a constant value. We attribute this optical Zener action to nonlinear refraction and absorption induced in the silicon by the intense picosecond pulses.