Delivery of radiation from a first transparent medium to a second transparent medium having a higher refraction index

摘要

Extraction of guided radiation from a waveguide (3) into a receiver chamber (1). The radiation arrives via a transparent medium and is extracted into the receiver chamber (1) holding a medium having smaller refraction index than the transparent medium, via a delivery waveguide (3) whose refraction index is equal to or greater than that of the transparent medium. The delivery waveguide (3) has a tapering radiation (5) delivery portion of non-circular cross sectional shape which projects into the receiver chamber (1).