Research On Tunable Erbium-doped Fiber Laser Based On Graphene/Graphene-Oxide

In recent times of big data, with the rapid development of optical fiber communication technology, the requirements of efficiency and reliability of information transmission for people is higher and higher. Tunable fiber laser as the light source in optical communication system is becoming a hot spot of research in recent years. New type of tunable fiber laser can play an important role for realizing the restructuring and upgrading of communication network. The tunable fiber laser will become the key component of all-optical network in the future.Since 2011, the two-dimensional carbon material-graphene, due to the unique properties shown in mechanics, thermotics, optics, and electrics, has been aroused widely attention in a variety of fields. In this thesis, in order to studying the optical characteristics of graphene and graphene oxide, several fabrication methods are designed and proposed. Then apply the graphene and graphene oxide to the tunable fiber laser according to their different optical properties. The main content of this thesis are as follows:1. The research background, research status at home and abroad is simply introduced. The characteristics of fiber laser are summarized and the advantage, development and tuning method of tunable fiber laser are also described.2. Apply the graphene and graphene oxide to the tunable fiber laser. The characteristics and properties of new material graphene and graphene oxide are introduced. According to these properties, some fabrication methods are summarized and two new methods are proposed, laying the foundation for the realization of the new material based fiber laser. Then the prospect for application in optical fiber communication system and development in the future of graphene and graphene oxide in the fiber laser is described in detail.3. A single wavelength tunable erbium-doped fiber laser based on core-offset structure is proposed. The fabricated core-offset structure is used as the fiber filter to generate the single wavelength laser. Meanwhile, due to the sensitive response of the core-offset structure to temperature, the laser can be tuned by changing the temperature. Afterward, a switchable and tunable erbium-doped fiber laser based on FBG and core-offset structure in parallel is proposed. By adjusting a variable optical attenuator, the laser can operate in dual-wavelength or in wavelength switching modes. Due to the sensitive response of the core-offset structure to curve, the wavelength can be tuned when the curve is applied on the structure. In addition, use the fabricated single-layer graphene as the saturable absorber to narrow the linewidth.4. A tunable multiwavelength erbium-doped fiber laser based on Lyot filter is proposed. Lyot structure is used as the fiber filter introduced into the ring cavity to generate the multiwavelength lasers. By analyzing the properties of Lyot, laser wavelength can be tuned by adjusting the polarization controller. The graphene oxide can perform a good nonlinear optical effect, which is benefit to suppress the mode competition caused by EDF and stabilize the multiwavelength output.