Highly nonlinear silica suspended core fibers

Abstract

Suspended-core fibers are systematically studied. We show that confinement loss in suspended-core fibers can be effectively reduced by an increase of air-cladding width for even sub-micron core diameters and, therefore, provides a considerable simpler solution than equivalent photonic crystal fibers with a large number of air holes for a wide range of nonlinear applications. We have further demonstrated a suspended-core silica fiber with core diameters of 1.27 microm and sub-dB splice loss to Hi1060. Loss at 1.55 microm was measured in this fiber to be 0.078 dB/m, a record for this small core diameter, limited mainly by scattering loss at the glass and air interface. The combination of high nonlinearity, low splice loss and low transmission loss of the suspended core silica fibers will enable a new class of low loss all-fiber nonlinear devices.