Modulation instability induced by cross-phase modulation in a dual-wavelength dispersion-managed soliton fiber ring laser

TL;DR

This paper demonstrates how cross-phase modulation causes modulation instability in a dual-wavelength dispersion-managed fiber laser, leading to tunable sidebands and new pulse dynamics, supported by experimental and theoretical analysis.

Contribution

It introduces a novel dual-wavelength fiber laser setup with femtosecond and picosecond pulses and analyzes the induced modulation instability both experimentally and theoretically.

Findings

Stable modulation sidebands appear due to cross-phase modulation.

Sideband intensities and wavelengths can be tuned by adjusting pulse power and wavelengths.

Theoretical analysis confirms the experimental observations.

Abstract

We report on the observation of modulation instability induced by cross-phase modulation in a dual-wavelength operation dispersion-managed soliton fiber ring laser with net negative cavity dispersion. The passively mode-locked operation is achieved by using nonlinear polarization rotation technique. A new type of dual-wavelength operation, where one is femtosecond pulse and the other is picosecond pulse operation, is obtained by properly rotating the polarization controllers. When the dual-wavelength pulses are simultaneously circulating in the laser ring cavity, a series of stable modulation sidebands appears in the picosecond pulse spectrum at longer wavelength with lower peak power due to modulation instability induced by cross-phase modulation between the two lasing wavelengths. Moreover, the intensities and wavelength shifts of the modulation sidebands can be tuned by varying the power of the femtosecond pulse or the lasing central wavelengths of the dual-wavelength pulses. The theoretical analysis of the modulation instability induced by cross-phase modulation in our fiber laser is also presented.