Study of Pulse Formation in an EDFL Under a Large Dispersion Variation Hybridly Mode-Locked by Graphene and Nonlinear Polarization Rotation

Abstract

In this work, we present a detailed experimental study of pulse formation mechanism in an EDFL, hybridly mode-locked by use of a CVD monolayer graphene onto a D-shaped optical fiber and nonlinear polarization rotation (NPR), under a large intracavity dispersion influence (up to 100 times) ranging from 12.3 to 1382 m cavity lengths. Analyzing the spectral evolution, temporal and soliton behaviors of the pulse, our results revealed the presence of four laser operating regimes with non-soliton and soliton formation from short to ultralong cavity lengths, all related to graphene/NPR nonlinearities, dispersion and soliton propagation influences.

Dual Regime Mode-Locked and Q-Switched Erbium-Doped Fiber Laser by Employing Graphene Filament–Chitin Film-Based Passive Saturable Absorber

“…Polarization controllers, although helpful in controlling the polarization of the laser output, and, thus, helping to obtain the mode-locked operation in multiple works, does add to the complexity of the fiber laser system and increase the system’s insertion loss. The limited range of adjustment of the polarization controller also limits its usefulness in certain applications [ 41 , 42 , 43 ]. The optical spectrum of the mode-locked pulse is depicted in Figure 13 , with the resolution of the OSA set at 0.02 nm.…”