Feasible fabrication of graphitic nano-layer saturable absorbers on fiber-ends for ultrashort pulse generation

Abstract

High-performance graphene based saturable absorbers with large modulation depth and high damage threshold are desired for mode-locked lasers. Here, we report direct growth of a graphitic nano-layer (GNL) on an optical fiber-end using plasma-enhanced chemical vapor deposition. The GNL exhibits outstanding nonlinear saturable absorption properties at 1.55 µm: a modulation depth of up to 28.3% and a large damage threshold. Stable modelocked pulses with pulse duration as short as 561 fs and spectral bandwidth of 4.86 nm are achieved. The results show that our fabrication method is promising for graphene based photonic applications.