| 摘要 |
<p>An optical grating is formed by exposing linearly spaced regions of an optical fibre (10), typically a germanosilicate core fibre, to UV irradiation to produce spaced apart regions (12 and 13) of differing refractive index within the core (11) of the fibre. The grating characteristics are modified to create a relatively complex structure, for example a ∏ phase-shifted distributed phase structure, by post-processing the grating. This is achieved by exposing at least one concomitant region (14) of the grating to localised UV irradiation.</p> |
