Spatial solitons in PT symmetric potential with competing gain and loss

Abstract

The existence and stability of fundamental, dipole and tripole solitons are investigated in parity-time symmetric potential with competing gain and loss. The competing parameter decides both the width of potential and loss or gain region. All these solitons exist in the potential with a suitable width. It is easy to form a fundamental soliton when increasing the parameter k. To form a dipole and a tripole soliton, the values of k should locate in some region. The multimode solitons are unstable for a larger power while may be stable for a relatively small one. The effects of competing gain or loss profile on the stability of these solitons are investigated with a linear stability analysis corroborated by a beam propagation method.