Gratings in Structured Optical Fibres

Figure 1

Typical structured optical fibres into which gratings have been written: (a) low-loss (<4 dB/km) 4-ring all-silica photonic crystal optical fibre; (b) 12-ring photonic crystal fibre with triangular core and photosensitive, high-NA step-index germanosilicate center; (c) simple Fresnel fibre; and (d) air-clad fibre with Yb³⁺-doped core.

(a)

(b)

(c)

(d)