Using Reduced Graphene Oxide to Generate Q-Switched Pulses in Er-Doped Fiber Laser

Using the reduced graphene oxide(rGO) as a saturable absorber(SA) in an Er-doped fiber(EDF) laser cavity,we obtain the Q-switching operation. The rGO SA is prepared by depositing the GO on fluorine mica(FM) using the thermal reduction method. The modulation depth of rGO/FM is measured to be 3.2%. By incorporating the rGO/FM film into the EDF laser cavity, we obtain stable Q-switched pulses. The shortest pulse duration is3.53 μs, and the maximum single pulse energy is 48.19 nJ. The long-term stability of working is well exhibited.The experimental results show that the rGO possesses potential photonics applications.     

Reduced graphene oxide as saturable absorbers for erbium-doped passively mode-locked fiber laser

We demonstrate a nanosecond mode-locked erbium-doped fiber laser(EDFL)based on a reduced graphene oxide(RGO)saturable absorber(SA).The RGO SA is prepared by depositing the graphene oxide(GO)on fluorine mica through thermal reduction of GO.A scanning electron microscope(SEM),Raman spectrometer,and x-ray photoelectron spectroscopy(XPS)are adopted to analyze the RGO characteristics.The results show that the reduction degree of graphene oxide is very high.By embedding the RGO SA into the EDFL cavity,a stable mode-locked fiber laser is achieved with a central wavelength of 1567.29 nm and repetition rate of 12.66 MHz.The maximum output power and the minimum pulse duration are measured to be 18.22 mW and 1.38 ns respectively.As far as we know,the maximum output power of18.22 mW is higher than those of other nanosecond mode-locked oscillators reported.Such a nanosecond pulse duration and megahertz repetition rate make this mode-locked erbium-doped fiber laser a suitable seed oscillator for high-power applications and chirped pulse amplifications.     

High-power passively Q-switched Nd:GdVO_4 laser with a reflective graphene oxide saturable absorber

A single output Q-switched Nd:GdVO4 laser with a reflective graphene oxide(GO) saturable absorber was demonstrated. The shortest pulse duration in the Q-switched laser is 115 ns, and the output power ranges from1.23 W at 1.71 MHz to 2.11 W at 2.50 MHz when the pump power rises from 7.40 to 10.90 W with the utilization of GO Langmuir–Blodgett(LB) films based on the convenient and low-cost LB technique. To the best of our knowledge, it is the highest output power in a Q-switched laser with a GO saturable absorber.     

800nm高能量飞秒激光脉冲刻写长周期光纤光栅机理

基于800nm飞秒激光脉冲对标准单模光纤采用非载氢技术刻写长周期光纤光栅的机理进行了研究.搭建了水平、垂直双CCD视频监控的飞秒激光脉冲逐点刻蚀长周期光纤光栅系统,研究了光栅长度、激光脉冲能量和光栅占空比等参数对光栅光谱特性的影响.研究结果表明,当光栅周期长度不变,光栅周期数和激光脉冲能量的变化使光栅谐振峰强度发生变化,光栅透射谱是单峰的;光栅占空比的改变导致光栅谐振峰由单峰转变为多峰.在谐振波长1 540nm处,得带谐振峰强度达到15dB、带外损耗不足2dB,在3dB衰减处带宽为15nm的谐振透射谱.