Simple Models of Self-Phase and Induced-Phase Modulation

T. Mirtchev

We present an analytical model of the self- and cross-phase-modulation-induced modulation instabilities in nonlinear, dispersive, homogeneously broadened, unsaturable fiber amplifiers. The rigorous treatment of the gain dispersion and of the gain-induced, near-resonance refractive-index dispersion permits description of the general case of arbitrary detuning between the laser frequency and the resonance and arbitrary bandwidth of the amplifying transition. Simple closed-form expressions are obtained for the combined gain coefficients and, in the self-phase-modulation-induced case only, for the integrated gain. A qualitatively new modulation-instability regime of an isolated wave in the normal group-velocity-dispersion region is described.

L.O. Silva, José Tito Mendonça

Masashi Ban, Toshihico Arimitsu

Mehrdad Mohebi, B. Jean-Jean, Jean‐Claude Diels

The reflection properties of an interface between a dielectric and a saturable dye solution are investigated. A simple phenomenological approach describes the switching behavior, including self-phase-modulation effects induced at the interface.

Toschihico Arimitsu, Masashi Ban, Fumiaki Shibata

Victor V. Kozlov, Evald E. Fradkin

The temporal envelope profile and the phase of a steady-state pulse propagating through a resonant medium in the presence of nonresonant nonlinearity are derived. The formation of solitonlike pulses takes place as a result of the balance of the self-phase modulation generated by nonresonant nonlinearity and the nonlinear resonant group-velocity dispersion induced by the self-induced-transparency effect in a resonant medium. Self-phase-modulation action leads to distortion of the pulse when its power and inverse duration exceed the critical values Pcr and τcr-1. We show the destructive role of self-phase modulation in the case of self-induced-transparency pulse generation in a laser with erbium-doped fiber as an intracavity coherent absorber.