Optical properties of high-delta air-silica microstructure optical fibers

We analyze the waveguide properties of microstructure optical fibers consis ting of a silica core surrounded by a single ring of large air holes. Altho ugh the fibers can support numerous transverse spatial modes, coupling betw een these modes even in the presence of large perturbations is prevented fo r small core dimensions, owing to a large wave-vector mismatch between the lowest-order modes. The result is an optical fiber that can appear single m ode with propagation properties that can be achieved only in multimode wave guides. (C) 2000 Optical Society of America OCIS codes: 060.0060, 190.0190, 320.0320.