Nonlinear optical shield
US5173811A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 11, 1991 |
| Grant date | Dec 22, 1992 |
| Priority date | — |
| Expiry date | Oct 11, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/3511
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical shield which is transparent to ambient light but which blocks high intensity light such as that from a laser, with a response speed on the order of several picoseconds or less, to provide eye protection and to protect light sensors from laser beams. The shield is a multilayer structure with layers in which colloidal silica particles are dispersed in a transparent polymer binder having an index of refraction close to that of the silica particles under ambient light conditions. The application of multiple sealant layers of pure binder material results in improved transmittance of ambient light. High intensity light such as that from a laser causes third order nonlinear optical effects, particularly photorefractive effects, in the silica which change its effective index of refraction so that the mismatch between the effective index of refraction of the silica and the index of refraction of the binder causes scattering of the incident light. The shield is effective over a broad radiation band including near infrared and ultraviolet portions of the spectrum as well as the entire visible light range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.