Mechanisms and advances of passive optical limiters

Passive optical limiters are devices that control the intensity of light by utilizing the nonlinearity of materials. They have applications in various fields including scientific research, defence and civilian usage. The effectiveness and limitations of reverse saturable absorption, two-photon absorption, free-carrier absorption, nonlinear refraction, induced scattering and photorefraction for passive optical limiters are discussed. Recent advances and future directions for passive optical limiters are briefly reviewed.