A light beam (6) is applied to a waveguide (3) in order to measure properties of the beam (6), e.g. the wavelength. According to the invention, the waveguide (3) has locally and/or time-varying resonances, e.g. by suitably designed grid couplers (4, 5). A light signal (7) is thus generated in the waveguide...http://www.google.de/patents/US5991480?utm_source=gb-gplus-sharePatent US5991480 - Process and device for measuring light beams
