摘要:
A device for selectively increasing higher-order mode losses comprises an optical fiber taper executed on a multi-mode fiber of a selected wavelength, and the fiber taper has separated regions, i.e. non-tapered fiber regions which have a first diameter equal to that of the main fiber. The tapered regions can also include transition regions in which the fiber diameter is reduced/increased, respectively, and a taper waist region which has a reduced diameter, where the taper level ratio between the regular diameter and the narrowed diameter is at least 20%, and the length of the transition regions are at least 0.5 mm on one side and may be zero on the other side, and the length of the taper waist with the narrower diameter is at least 0.5 mm. Furthermore, the taper area is coated with a filtering substance with attenuating properties between the tapered section and the cladding.
摘要:
Microstructured optical fibre with selectively enlarged spaces of reduced refraction index, especially for the generation of non-linear effects and stress measurements with a ring configuration of spaces, located around a cladded core, where the spaces demonstrate cross-section shape close to circle and decreased diffraction index, especially for the generation of non-linear effects and stress measurements, made of glass, preferably of silica glass or polymer and are located in nodes of hexagonal lattice with distances between the lattice nodes equal to the lattice constant, in which, around a single-mode core, there are, at least two rings with spaces of decreased diffraction index, filled with gas or fluid or a polymer, where the diameter of every-second space with decreased diffraction index in, at least, one ring, is enlarged to be lower from the double lattice constant, while the diameters D of all the enlarged spaces with decreased diffraction index are similar in size and the diameters d of non enlarged spaces with decreased diffraction index are close in size and lower from the lattice constant and the ratio of the diameter d of non enlarged space to the lattice constant is within the range from 0.30 to 0.45.