The optical process for analyzing substances is based on the measurement of the propagation properties of optical surface waves on sensor surfaces. In a wave guide layer structure in contact with a sample, guided light waves are decoupled with a grating coupler. The decoupling region of the grating coupler...http://www.google.com.au/patents/US5479260?utm_source=gb-gplus-sharePatent US5479260 - Optical process and apparatus for analysis of substances on sensor surfaces
