Eur. Phys. J. D (2015) 69: 96
https://doi.org/10.1140/epjd/e2015-50471-7

Regular Article

Long cavity and low repetition rate passively mode-locked fiber laser with high-energy right angle trapezoid shaped soliton in anomalous dispersion regime

¹ School of Electronic Engineering, Xi’an University of Posts & Telecommunications, Xi’an, Shaanxi 710121, P.R. China
² School of Physics and Mechanical & Electronic Engineering, Xi’an University, Xi’an, Shaanxi 710065, P.R. China
³ Institute of Physics & Optoelectronics Technology, Baoji University of Arts and Sciences, Baoji, Shaanxi 721013, P.R. China

^a e-mail: luowenfeng@xupt.edu.cn

Received: 22 June 2014
Received in final form: 4 December 2014
Published online: 2 April 2015

Abstract

A long cavity passively mode locked fiber laser in the anomalous dispersion regime is reported. Nonlinear polarization rotation technique is employed to achieve the mode locking in our experiments. The output pulse from the fiber laser has the Gaussian profile spectrum and right angle trapezoid shape. Stable mode locking is achieved without using any dispersion-compensation components. The single pulse with an energy of 652 nJ and a repetition rate of 836 kHz at the pump power of approximately 500 mW is obtained and the duration of the output pulse increases linearly with the pump power. Different from the conventional low-energy soliton pulse, experimental results demonstrate that the passively mode locked fiber laser operating in the anomalous regime can also realize high energy pulse.