Mode locked oscillation in ultrafast fiber laser using bilayer graphene saturable absorbers

Abstract

Graphene has emerged as a promising candidate for using in ultrafast fiber lasers from which optical properties of graphene nowadays are investigated in laboratory. As graphene has zero bandgap, two layer of graphene is used to open a bandgap which is called bilayer graphene. One extraordinary feature of bilayer graphene is ultra-short pulse in fiber laser that is boon to the field of microscopy, medical diagnosis, and imaging. In this work we will fast calculate a fundamental frequency of laser signal and corresponding ultrafast signal response time. We will analyze our work based on two frequencies like i) fundamental frequency ii) reference oscillating frequency. At first we will observe the mode locked oscillation or oscillating electric signal in fiber by varying ultra-shot response time. We will also vary the fundamental frequency from its reference oscillating frequency and observe mode locked oscillation. For the sake of clear understanding we will also observe the average power of the mode locked oscillating signal. At last we will use a moving average filter to smooth out this average power signal. From which we will approach a decision that, for which fundamental frequency the mode locked oscillated signal will diverge in all around and for which fundamental frequency the mode locked oscillated wave will converge into a point.