Process for making a solid optical limiter containing a graded distribution of reverse saturable material
US5391329A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 1993 |
| Grant date | Feb 21, 1995 |
| Priority date | — |
| Expiry date | Aug 23, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB32B2551/00
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An improved process is provided for making optical limiters having a graded axial distribution of a reverse saturable absorber compound, such as a buckminsterfullerene, in a host matrix, such as polymethyl methacrylate or polycarbonate. The process of the invention includes: (a) dissolving the reverse saturable absorber and the host matrix in a suitable solvent to form a solution having a preselected ratio of reverse saturable absorber to host matrix; (b) casting the solution onto a surface to form a film; (c) evaporating the solvent to form a free-standing film; (d) performing steps (a)-(c) for each different desired ratio of reverse saturable absorber to host matrix; (e) stacking the free-standing films in a desired order; and (f) hot-pressing the stack to form the optical limiter having a graded distribution of the reverse saturable absorber in the host matrix. If desired, the stack of films can be placed in a die for hot-pressing. The films can be pre-cut to the shape of the die.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.