Abstract

Hill and coworkers¹ have discovered that an argon laser beam can produce a Bragg grating in G-doped silica fibre leading to almost total reflection of the pump light. Despite considerable interest to the phenomenon stimulated by possible applications and a large body of studies (see a review²), the nature of the formation of these gratings remains obscure. The stationary models² imply the local response and cannot explain the observed growth of the reflected light. The theory³ based on the non-stationary model shows the growth of the grating. This theory, however, does not take into account the relaxation process leading to saturation of the refractive index and can be valid only for early stages of the grating formation.

© 1994 IEEE