Optical Nondestructive Method for Dynamic Monitoring of Chemical Reactions
Original Publication Date: 1983-Mar-01
Included in the Prior Art Database: 2005-Feb-06
By placing a reactive film (e.g., a polymeric film) or a nonreactive film with a reactant upon the surface or adjacent to a prism or grating coated with silver, gold (about 500 Angstroms thick) or other highly reflecting metal (aluminum or copper) with or without a protective coating, the waveguide modes can be monitored as a function of chemical reaction caused or influenced by heat, light, charge, current (electrochemical), electric field, and/or diffusion of reagent. As a chemical reaction, e.g., polymerization, curing, hardening, loss of solvent, cross-linking, decomposing, or degrading proceeds, changes in thickness, refractive index, including an anisotropy in the index between in-plane and perpendicular to the plane, and absorption, can be process monitored in a nondestructive way.