OPTICAL STRUCTURE FOR MULTI-PHOTON EXCITATION AND THE USE THEREOF

The invention relates to a variable embodiment of an optical structure, comprising an optical waveguide with a waveguiding layer (a), being optically transparent at least at an excitation wavelength, wherein the intensity of an excitation light in-coupled into layer (a) and guided in layer (a) is high enough within layer (a) and on layer (a), that molecules located on the surface of layer (a) or within a distance of less than 200 nm, which are capable of luminescence and/or photo-reactive, can be excited by multi-photon excitation, preferably by two-photon excitation. Thereby, embodiments are preferred which allow for a multi-photon excitation along macroscopic distances or on extended surfaces, along the trace of the excitation light guided in layer (a). The invention is also related to different embodiments of optical systems and of analytical systems with an excitation light source and an embodiment of an optical structure according to the invention, as well as to methods based thereon, especially for luminescence excitation and for the determination of one or more analytes by luminescence detection after multi-photon excitation, and its use.