Stability of bright solitons in optical system supported by cubic and quintic nonlinearities with P T -symmetric quartic harmonic complex potential

Abstract

Abstract This work analyzed the existence and stability of optical waves in linear and nonlinear media with self-focusing cubic-quintic nonlinearity by way of interactions of nonlinearity, spatial diffraction, and parity-time ( P T ) symmetric complex potential defined by quartic harmonic real potential and Gaussian imaginary distribution. We demonstrated that the order of nonlinear function, the width and depth of the real potential, and the coefficient of diffraction modify the span of the complex potential parameter onto which P T -symmetry breakdown occurs. The region of stable P T -symmetry in the self-focusing medium improves as the order of the nonlinear function increases, as demonstrated by comparing the soliton solutions with cubic and quintic nonlinearities. We addressed the nonlinear evolution of the stable and unstable P T solitons under propagation. The linear stability of bright solitons is extensively studied and established the conditions for stable soliton for both P T − symmetric and broken P T − symmetric regions.