RAMAN FIBRE-OPTICAL LASER, BRAGG FIBRE-OPTICAL GRATING AND A METHOD OF ALTERING THE REFRACTIVE INDEX IN GERMANO-SILICATE GLASS

摘要

The inventions relate to the sphere of the laser technology, the fibre and integrated optics, and are industrially applicable in elements of the fibre and waveguide optics made of germanium silicate glass, particularly in fibre-optical Bragg gratings and long-spacing gratings, scattering compensators, integrated optical waveguides, etc. The objective of simplification of Raman fibre lasers emitting in the wavelengths of 1.24 mc and 1.48 mc and enhancement of the radiation conversion efficiency in Raman scattering is attained. A laser emitting in the wavelength of 1.24 mc comprises a pumping source (1), a fibre light guide (2) containing P2O5 in the amount from 1 to 30 mole %, portions of a fibre light guide that contain GeO2 in the amount from 11 to 39 mole % and are Bragg fibre-optical gratings (3) and (4), grating (3) forming a blank distributed reflector of an optical resonator for first Stokes component, and grating (4) - the output distributed reflector for the same resonator. First Stokes component is derived at the output. In a Raman fibre laser emitting in the wavelength of 1.48 mc second Stokes component is derived. A change in the refraction index in a portion of a fibre light guide (11) is achieved by directing to it a laser radiation (12) having a wavelength from 270 to 390 nm that passes through a protection polymer cladding of a fibre light guide (11).