Sj. Hewlett et al., CLADDING-MODE COUPLING CHARACTERISTICS OF BRAGG GRATINGS IN DEPRESSED-CLADDING FIBER, Electronics Letters, 31(10), 1995, pp. 820-822
Experimental transmission spectra of W-written Bragg gratings in depre
ssed-cladding fibre are characterised. The fine-structure features on
the short-wavelength side of the fundamental Bragg line are shown to b
e due to coupling between the LP(0l) and higher-order LP(0n) and LP(1n
) modes.