Dual-core photonic crystal fibre

Summary form only given. In order to study the coupling between guided modes in multicore photonic crystal fibers (PCF) and to verify the predictions of the effective index model for PCF, we have fabricated a photonic crystal fiber with two closely coupled cores. We investigated the coupling between the guided modes in these fibers using tunable single-frequency diode laser light, focused onto just one core at the input face. We then monitored the intensity of the light in each of the cores at the output face of the fiber, as the wavelength of the diode laser was scanned.