Fig. 1. Cross-section of photonic crystal fiber

Fig. 2. Cross-section of taper beams of melt fiber

Fig. 3. (a) Spliced point of photonic crystal fiber and taper rod; (b) physical map

Fig. 4. Experimental setup of integrated double-cladding photonic crystal fiber amplifier

Fig. 5. Relationship between output power and pump power

Fig. 6. Spectrum after dichroscope

Fig. 7. Spot pattern obtained by spot analyzer