Simultaneous scalar and cross-phase modulation instabilities in highly birefringent photonic crystal fiber

A Kudlinski,R T Murray,A Mussot,D Labat,S Virally,E J R Kelleher,A Bendahmane

doi:10.1364/oe.21.008437

Abstract

We report the experimental observation of scalar and cross-phase modulation instabilities by pumping a highly birefringent photonic crystal fiber in the normal dispersion regime at 45° to its principal polarization axes. Five sideband pairs (two scalar and three vector ones) are observed simultaneously in the spontaneous regime, four of which have a large frequency shift from the pump, in the range 79-93 THz. These results are in excellent agreement with phase-matching arguments and numerical simulations.

Highlights

Modulation instability (MI) is a physical process in which the steady state of a system is destabilized by a weak perturbation at a different frequency, as a result of a balance between linear and nonlinear (NL) effects [1]
Typical features of polarization MI (PMI) include the fact that both sidebands have the same polarization state, which is orthogonal to the polarization state of the pump, and that their generation from a pump located in the normal dispersion regime has a power threshold, on the contrary to scalar MI
We focus on scalar MI (SMI) [5] and XPMI processes assisted by higher-order dispersion [16] in a highly birefringent photonic crystal fibers (PCFs)

Summary

Introduction

Modulation instability (MI) is a physical process in which the steady state of a system is destabilized by a weak perturbation at a different frequency, as a result of a balance between linear and nonlinear (NL) effects [1]. Typical features of PMI include the fact that both sidebands have the same polarization state, which is orthogonal to the polarization state of the pump (see Table 1), and that their generation from a pump located in the normal dispersion regime has a power threshold, on the contrary to scalar MI. Spontaneous XPMI [20] and PMI [21] in PCFs were first reported by pumping in the normal dispersion region They were followed by the demonstration of a new regime in which higher-order dispersion allowed for very large XPMI shifts (about 100 THz) [16,22] which had to be seeded to be observed beyond. We report the simultaneous observation of 5 sidebands pairs (2 from SMI and 3 from XPMI, all spontaneously) by pumping at a specific region in the normal dispersion regime of a PCF with tailored dispersion and birefringence properties

Fiber design

Numerical results

Discussion and conclusion