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Study On Yarn - Doped Yb - Doped Fiber Laser With Quartz Carbide

Posted on:2016-02-25Degree:MasterType:Thesis
Country:ChinaCandidate:S S HuangFull Text:PDF
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Pulsed fiber lasers not only can generate high-peak power optical pulses but also possess some attractive characteristics, such as compact structure, high-quality optical beam, adjustment-free configuration, and cheap. As a saturable absorber(SA) of graphene derivatives, graphene-oxide(GO) not only has all the characteristics of ultrafast recovery time,high damage threshold and broadband saturable absorption, but also much easier and cheaper to obtain. Passively mode-locked fiber laser based on Go is one of the best platforms for studying nonlinear optics phenomena, the phenomena including harmonic mode-locking(HML), dissipative soliton resonance(DSR), multi-wavelength mode-locking and so on. They have the potential applications in optical signal processing, biomedical research, fiber sensing, spectroscopy, wavelength-division-multiplexed(WDM), optical fiber communication systems, material processing, remote sensing, light detection systems and measurement instruments. In this paper, passively mode-locked Yb-doped fiber(YDF) laser based on a GOSA in all normal dispersion is the research platform. We not only experimentally investigated several different operating modes from the laser, but also explained them theoretically. The main works are as follows: 1. We firstly present several modes and features of mode-locked fiber lasers. Additionally, we focus on presenting the research progresses of passively mode-locked fiber lasers based on graphene and GO. 2. We analysis the band structure and the SA principle of graphene. We also present the optical properties of GO, and come to a conclusion that GO as SA is advantageous could come up to graphene. 3. We firstly introduce several ripping methods of graphene. Secondly, we present the fabrication details of a GO and its linear and nonlinear absorbance characteristics, the GO is used in our experiments. 4. We fabricate an YDF laser with GOSA, not only obtain the mode-locked picosecond pulses with fundamental frequency of 1.062 MHz, but also achieve harmonic mode-locking with different orders. In the experiment, the harmonic number can be tunable by changing pump power and the polarization controller(PC), the highest 309th-order harmonic is about 328 MHz. We also investigate the relationship between spectral bandwidths and harmonic numbers. 5. We observe the DSR in a passively mode-locked YDF laser based on GOSA. Increasing the pump power, the square pulse duration can be increased from 3.2 ns to 7.4 ns without changing the amplitude. The fundamental frequency is about 1.072 MHz. Under the maximum pump power of 500 m W, the output pulse energy is 2.43 n J, the pulse energy is 9.7 n J in cavity. In the experiment, we also explore the square pulse broadening, 3 d B spectral bandwidth, pulse energy, and output power with respect to the pump power. 6. We explore the generation of tunable single-, switchable and tunable dual-, and stable triple-wavelength dissipative solitons(DSs) in an all-normal-dispersion mode-locked YDF laser based on a GOSA. The tunable single-wavelength DS have a wide wavelength-tunable range of 16.4 nm. The corresponding fundamental frequency with a signal-to-noise ratio(SNR) of high than 65 d B. The dual-wavelength DSs not only have a wavelength-tunable range(about 10 nm) but also have variable wavelength spacing(3.8-13.8 nm). The signal-to-noise ratios of the dual-wavelength DSs are high than 62 d B. The formation dynamics of the multi-wavelength DSs is also investigated experimentally.
Keywords/Search Tags:graphene/graphene-oxide saturable absorber, Yb-doped fiber, harmonic mode-locking, dissipative soliton resonance, multi-wavelength dissipative solitons
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