Experimental investigation of tunable all-solid photonic bandgap fiber coupler

Abstract

The fabrication of a tunable all-solid photonic bandgap fiber coupler based on side-polishing technique is reported. The all-solid photonic bandgap fiber is set into a silica block and then polished to access the evanescent field. The photonic bandgap fiber coupler was assembled by mating two identical half-blocks with each other. By longitudinally adjusting the relative position between the mated pair, the tunable coupling ratio as much as 92.5% at 1550 nm is achieved. The investigation of the spectrum properties shows that the coupler has excellent tunability properties, for which the coupling ratio can be smoothly and continuously tuned.