In this paper, tin disulfide （SnS2）, a two-dimensional （2D） n-type direct bandgap layered metal dichalcogenide with a gap value of 2.24 eV, was employed as a saturable absorber. Its appearance and nonlinear saturable ab- sorption characteristics were also investigated experimentally. SnSz-PVA （polyvinyl alcohol） film was successfully prepared and employed as a mode-locker for achieving a mode-locked Er-doped fiber laser with a pulse width of 623 fs at a pulse repetition rate of 29.33 MHz. The results prove that SnS2 nanosheets will have wide potential ultrafast photonic applications due to their suitable bandgap value and excellent nonlinear saturable absorption characteristics.
A molybdenum disulfide（Mo S2） saturable absorber was fabricated by thermally decomposing the ammonium thiomolybdate. By using the MoS2 absorber, a compact diode-pumped passively Q-switched Tm:GdVO4 laser has been demonstrated. A stable Q-switched laser with repetition rates from 25.58 to 48.09 kHz was achieved.Maximum average output power was 100 mW with the shortest pulse duration of 0.8 μs. Maximum pulse energy is 2.08 μJat center of 1902 nm.
Pingguang GeJie LiuShouzhen JiangYuanyuan XuBaoyuan Man
以新型金纳米材料为可饱和吸收体,研究了LD端面泵浦的Nd:YSAG被动调Q激光器的激光输出特性。实验中通过调整金纳米棒的长径比等参数,成功地将金纳米棒材料由表面等离子体共振引起的非线性吸收峰调控到Nd:YSAG激光的输出波长1 062 nm处,并成功获得了稳定的被动调Q激光输出,在泵浦功率为4.9 W时,激光器的平均输出功率为14 m W,此时,激光脉冲宽度为944.1 ns,重复频率100.1 k Hz。实验结果表明,金纳米材料在脉冲激光领域具有良好的应用前景。
研究了激光二极管端面泵浦Nd:YVO4/Ga As被动调Q激光器的输出特性。在连续光运转和调Q运转情况下,得到的激光最高输出斜效率分别为41.5%和11.4%。用一片700μm厚的Ga As薄片作为饱和吸收体,对1.06μm激光透过率为6.5%的平面镜作为15 mm谐振腔的耦合输出镜,得到的最短脉宽仅为1.9 ns。在泵浦功率由0.5 W上升到5.6 W的过程中,用T为6.5%和20%的输出镜得到的脉冲重复频率从18.7和23.9 k Hz分别上升到53和41.3 k Hz。两种输出镜透过率下得到的最大脉冲能量分别为8.5和13.3μJ,相应的峰值功率高达4.45和4.6 k W。此激光器具有非常高的振幅稳定性,在高泵浦功率下调Q脉冲振幅波动小于3%。
1.4μm人眼安全激光具有对人眼安全、对烟雾环境穿透能力强以及易于产生和探测等特点。本文基于Nd:LGGG新晶体,采用石墨烯作为可饱和吸收体,研究了1.4μm人眼安全激光输出特性。在注入泵浦光功率15.6 W时,获得2.38 W的1.4μm连续激光输出,光-光转换效率为15.4%;在注入泵浦光功率14.3 W时,获得平均功率为255 m W的1.4μm调Q激光输出,输出脉冲宽度为490 ns,重复频率为80 k Hz,激光单脉冲能量为3.2μJ,脉冲峰值功率6.53 W。
