Patent ID: 8478087

Claim:
An optical power limiter comprising an input optical transmission element, an output optical transmission element, and a power-limiting element disposed between said input and output elements for transmitting optical signals from said input element to said output element, said power-limiting element comprising an optically transparent solid dielectric matrix material having a refractive index that changes with temperature and containing dispersed light-absorbing nano-powder particles of at least one material that is reversibly heated in response to light above a predetermined optical power level, the heating of said solid nano-powder particles in turn heating said matrix material to produce non-linear changes in the refractive index of said matrix material due to thermal gradients between particles and thereby changing the optical transmission properties of said power-limiting element, said particles having a diameter of less than 0.1 micron and said material being at least one element selected from the group consisting of Ag, Au, Ni, Va, Ti, Co, Cr, C, Re and Si.