Photonic Crystals: Intensity-Dependent Transmission Protects Sensors

摘要

Nonlinear absorption properties make photonic crystals useful optical limiters where protection is needed from sudden flashes of high- intensity light. Optical limiters are devices that exhibit high transmission at normal light intensities and a transmission that decreases as the light intensity rises. This intensity-dependent transmission can keep the transmitted light energy below some maximum value. The devices can perform several useful optical functions, the most obvious of which is protecting optical elements and sensors, including the eyes, from damage by sudden flashes of highintensity light. Desirable properties of a limiter include a low threshold, a fast response, and wide dynamic and transmission ranges.