Two wavelength operation of a nonlinear fiber loop mirror

Abstract

The nonlinear fiber loop mirror has been shown to be a useful device for demonstrating nonlinear optical switching. Following on from the theoretical work1 a number of experimental results have been published. These have included long pulse (quasi-cw) switching and recently complete pulse switching using solitons.2 Examples were single source but it is possible to use a source at one wavelength to switch a low power signal of another wavelength and this is the situation we have investigated. The switching power is provided by a mode-locked Nd:YAG laser at 1.32 µm and the switched signal is from an F-center laser operating at 1.53 µm. We present results showing up to four switching cycles of the 1.53-µm source, the number of cycles being eventually limited by the onset of Raman generation. This arrangement of the nonlinear loop mirror represents a method of modulating one signal with another merely by using a coupler and a length of optical fiber.