Optical Limiters Without Focal Planes

We propose to develop light weight optical limiters without focusing lens that provides sufficient attenuation, optical limiting >=104, at incident radiation levels that would otherwise cause retinal injury. At the same time it maintains a ground state transmittance of 50%. These optical limiters will have a tremendous improvement on the safety of the solders and the commercial laser operators. In the proposed optical limiter without focal plane the high energy beam is diffused on the substrate plan and off the optical axis of the limiter due to destructive interference of the high energy beam induced by optical nonlinear material. As the incident radiation increases by one fold the nonlinear phase increases by multiple folds, nonlinear effect, as result less and less radiation is transmitted and more radiation is diffused in the substrate. The phase nonlinearity is orders of magnitude higher than the nonlinear absorption from e.g. reverse saturable absorbers (RSA’s) or though two photon absorption (2PA). Furthermore, the nonlinear phase shift is highly sensitive and has a nonlinear energy threshold that is order of magnitude lower than the nonlinear absorption threshold. Therefore the nonlinear phase interferometers effect, which occurs at low optical radiation level below retinal damage threshold, enables the design of optical limiters without focal plan, a clever design allows the optical limiter to be light weight on thin substrate. This is the first time to our knowledge such an optical limiter is proposed. This proposed optical limiter without focal plane will be of immediate use for as a passive filter for visible in IR spectrum optical sensors protection and as a goggles in any field that employs high energy laser eye protection, e.g. medical laser surgery, dental laser surgery, laser operators, lab technicians, laser welding, manufacturing, and laser researchers.