We have achieved an all-optical tuning in photonic crystal fiber (PCF) by filling the photoresponsive liquid crystal (LC)
into the air-hole cladding. The photo-induced phase transformation of the photoresponsive LC modulates the effective
refractive index of the photoresponsive LC-filled air-hole cladding, thereby creating an optically tunable environment.
Under the laser irradiation the output intensity of guided light can be modulated by the photoresponsive LC-filled
photonic bandgap structure. The tuning behavior of the guided light is independent on the polarization direction by using
the linear-polarized He-Ne laser as probe. We also demonstrate the potential use of photoresponsive LC-filled PCF in
all-optical communication device using an optical spectrum of wide bandwidth amplified from an erbium-doped fiber
amplifier (EDFA) system.