Patent ID: 6873764
Filing Date: 2005-03-29
Classification: G01N,G02B

Abstract:
1. Evanescent field sensor plate with a platelike substrate with, on a surface portion, a plurality of continuous coupling gratings each formed as a line grating with a grating period between 150 nm and 2000 nm, the coupling gratings being parallel to each other and extending over at least 0.5 cm, and the platelike substrate bears a transparent layer with a refractive index different from that of the substrate, wherein a coupling angle (θ) at which a light beam directed through the substrate to the coupling grating is coupled with the transparent layer with maximum coupling efficiency changes by at most 0.05°/cm along the line grating and the absolute value of deviation of the coupling angle (θ) from a required value on the evanescent field sensor plate does not exceed 0.5°.