Graphene saturable absorber based all-polarization maintaining Er-doped fiber mode-locked laser

Mechanically exfoliated graphene saturable absorber based all-polarization maintaining passively mode-locked erbium doped fiber laser is presented. The laser consists of fully polarization maintaining (PM) fibers and components, providing linear output polarization state. The saturable absorber was formed by mechanical exfoliation of graphene flakes from pure graphite and deposited on a fiber connector. It was characterized using atomic force microscopy and Raman spectroscopy. Laser resonators with repetition frequency of 45.88 MHz and 114.1 MHz were investigated. The soliton pulses at 1555 nm were achieved with duration around 600 fs. The splicing procedure of PM-fibers was also optimized which results in improvement of degree of polarization (DOP).