共查询到18条相似文献，搜索用时 62 毫秒
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石英基掺Tm3+包层抽运光纤激光器 总被引：1，自引：0，他引：1
在MCVD车床上利用“湿法”掺杂方法研制出纤芯高掺Ge的石英基掺Tm3+光纤预制棒,采用侧面研磨和抛光工艺制成横截面为正六边形的光纤预制棒.经拉丝,内层涂覆低折射率材料后制成包层抽运光纤.测试其吸收谱,并对光纤参数进行优化.通过在光纤两端紫外写入光纤Bragg光栅,制成线形光学谐振腔,在工作波长793nm的激光抽运下,获得工作波长1947.1031nm、功率2.05W的激光输出.由此证明这种光纤具有优异的光学特性.关键词：3+光纤')\" href=\"#\">石英基掺Tm3+光纤光纤Bragg光栅包层抽运光纤激光器 相似文献
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利用非线性光环形镜（NOLM）的可饱和吸收特性实现了可自启动的2 m全光纤高能量被动锁模掺铥光纤激光器。当泵浦功率大于3 W时,激光器工作在连续或不稳定脉冲运转状态;泵浦功率达到4.69 W后,输出为自启动锁模脉冲,重复频率4.26 MHz,中心波长2 061.5 nm,光谱半极大宽度18.1 nm,平均输出功率8.8 mW;继续增加泵浦功率到最大值7.56 W,可以得到中心波长2 062.2 nm、光谱半极大宽度17.1 nm、斜率效率为6.2%、脉冲宽度和能量分别为424 fs和65.6 nJ的稳定锁模脉冲。这是目前已报道的在未经放大情况下脉冲能量最高的2 m锁模脉冲光纤激光器。 相似文献
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龙井宇;沈德元;王屹山;赵卫;郭成正 《光子学报》2013,42(10):1147-1151
为了实现掺Tm光纤激光器的高功率连续运转,需要解决半导体激光器输出的低光束质量泵浦光到增益光纤包层的高效耦合问题,以及增益光纤的热管理问题.利用柱面透镜组成的望远镜光学系统对半导体激光器输出泵浦光束进行扩束,使其水平方向的光束发散角获得降低,利用45°反射切割镜对扩束后的光束进行切割,经整形处理后水平方向的光束参量积为84mm·mrad,实现了约70%的光纤端面耦合传输效率.设计了两段增益光纤串联的结构,增加了泵浦光接收端面数,获得了528W的可用泵浦功率.光纤的热管理方面,在泵浦光的输入端部(约250mm),采用了水冷金属热沉散热.基于该实验装置,利用总长度6.4m的掺Tm增益光纤,获得了最高280W的连续输出功率,激光中心波长2015nm,对应于耦合泵浦功率的斜率效率达55.6%.实验结果表明:通过对半导体泵浦光束的整形处理,可以提高光束对增益光纤的耦合传输效率;双光纤串联的结构在增加可用泵浦功率的同时,降低了光纤端部的热负载,并使整个光纤长度上的热分布更加均匀. 相似文献
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包层泵浦的L波段Er3+/Yb3+共掺光纤激光器 总被引：1，自引：4，他引：1
报道了一种工作波长在L波段的包层泵浦Er3+/Yb3+共掺光纤环形激光器. 环形腔内的激光工作介质为一段9 m长的Er3+/Yb3+共掺高掺杂光纤. 利用6个976 nm LD同时抽运前段Er3+/Yb3+共掺双包层光纤产生的放大自发辐射谱作二次抽运源, 使腔内增义谱由C波段移到L波段, 实现了L波段光纤激光器的稳定输出; 采用包层泵浦技术, 在抽运功率为3594.5 mW时, 测得泵浦入纤功率为2731.8 mW, 实现了输出连续功率最大518.4 mW,斜率效率达到19% 的激光输出; 所形成激光的工作波长为1613.94 nm, 激光光谱的3 dB带宽为1.5 nm, 边模抑制比接近于50 dB. 相似文献
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ZHU Decai;HU Yaozong;ZHOU Lewen;HUANG Changqing;DONG Xinyong 《光子学报》2022,51(11):117-123
Random Fiber Lasers （RFLs） based on random distributed feedback can operate without a precise resonant cavity, leading to the advantages of simple structure and low production cost. In previous work, random fiber lasers operating in the band of 1.0~1.6 μm have been widely investigated. However, limited by the high transmission loss of ~30 dB/km and the weak Rayleigh scattering efficiency in normal silica fibers, random fiber lasers operating in the band of 2 μm are rarely reported. It’s of great fundamental interest to push the random fiber lasers to 2 μm mid-infrared band for their potential applications in the fields including medical surgery, nonlinear optics, material processing, and remote sensing. In this work, a random fiber laser operating in 2 μm band is developed by using a 1.5 m long thulium-doped fiber as the gain medium and a fiber random grating for random distributed feedback with enhanced Rayleigh scattering efficiency. The proposed random fiber laser adopts the half-open cavity design by using a high reflectivity fiber Bragg grating with a central wavelength of 1 940 nm to provide strong feedback to the laser system. A 793 nm semiconductor laser is employed as the pump laser source. The fiber random grating containing over 6 000 refractive index distortion spots was inscribed point by point along with a 10 cm long single-mode fiber by using a Ti：sapphire femtosecond regenerative amplifier with an operation wavelength of 800 nm, a repetition rate of 100 Hz and a pulse duration of 80 fs. The neighboring refractive index distortion points were spaced at a random distance between 7.5 and 12.5 µm. Experimental results show that random laser output at the wavelength of 1 940 nm is achieved with a relatively low threshold power of 2.33 W. Benefit from the enhanced Rayleigh scattering efficiency of the fiber random grating, the pump threshold of the random fiber laser is much lower than that of the previously reported random fiber laser in 2 μm region. With increasing the pump power, an output power of the random fiber laser increases nearly linearly with a slope efficiency of 4%. When the pump power reaches 3.8 W, the output power is 57 mW and the optical signal-to-noise ratio is up to 56 dB. The laser output wavelength remains quite stable during the change of pump power. To further test the stability of the random fiber laser, laser output spectra and powers were measured at an interval of 5 min and one second respectively within 60 min under the fixed pump power of 3.8 W. Good wavelength stability of 0.1 nm and power stability of fluctuation less than 0.26 dB are achieved. The good performance in stability should be related to the good wavelength selectivity and stability of the high-reflectivity fiber Bragg grating in both wavelength and reflectivity. It was fabricated on ordinary single-mode fiber, not the thulium-doped fiber, so its reflection wavelength and reflectivity can keep stable even when the pump laser reaches new heights and changes the temperature of the thulium-doped fiber. The slope efficiency is relatively low if compared with that of the common thulium-doped fiber lasers. It should be related to the relatively large insertion losses, 7.5 dB in total, of the two fiber fusion splicing points between the pump laser source and the thulium-doped fiber. The fiber parameters of the lead-out fiber of the pump laser and the thulium-doped fiber are much different from those of the single-mode fiber of the ports of the wavelength-division multiplexer. However, it can be improved by customizing a wavelength-division multiplexer with matching fiber parameters. Anyway, the proposed random fiber laser provides an effective technical method to develop random fiber lasers in the 2 μm wavelength band with relatively low pump threshold and better performances. 相似文献
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以熔融淬冷法自制了Tm~(3+)掺杂Ge-Ga-S硫系玻璃,并以此为基质材料,用漂浮粉料熔融法制备了直径分布为50—200μm的高品质因数(Q10~4)的有源硫系玻璃微球谐振腔.在显微镜下优选出一颗表面质量好、球形度较高、直径为72.84μm的微球,与氢氧焰扫描拉锥法制备的一根腰锥直径为1.93μm的石英光纤锥进行近场耦合.根据基质材料的吸收光谱特性,选用808 nm的半导体激光器作为抽运源.实验测得光纤锥倏逝波场激发出了掺Tm~(3+)硫系玻璃微球在1460 nm附近的荧光回廊模式,其典型共振峰间隔为4.39 nm.实验测得的荧光回廊模式与米氏散射理论计算结果符合度较高(最大误差仅为0.047%),验证了本文提出的掺Tm~(3+)硫系微球制备及耦合工艺的可行性. 相似文献
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掺铒光纤非线性折射率的理论研究 总被引：1，自引：0，他引：1
建立了掺杂光纤折射率的普适公式，并利用激光运动方程，推导出折射率随泵浦光强的变化关系，给出了在典型参数下的折射率－光功率变化曲线。发现，在激光中心频率１．５３μｍ附近，当泵浦光强远大于泵浦阈值时，掺铒光纤折射率变化量在１０＾－７量级，这比在相同泵浦光克尔效应引起的变化大３０倍左右，并且这一变化量存在极限，这一极限由掺铒光纤的特性参数唯一确定。 相似文献
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用坩埚下降法生长获得了尺寸为φ25mm×90mm、Tm2O3初始掺杂摩尔分数为0.5%的CdWO4单晶。晶体的颜色由上部血红色逐渐加深至下部的黑褐色。对不同部位的晶体薄片进行800℃的氧化处理,测定了处理前后不同部位的吸收光谱和FTIR红外光谱。经氧气退火处理后,由于氧空位缺陷减少,晶体的颜色明显变淡。在吸收光谱中观测到421,684,805nm的吸收带。其中421nm的吸收峰随退火温度的升高而逐步减弱,经800℃处理后基本消失。在808nm激光二极管激发下,观察到中心波长为1.5μm和1.8μm的荧光发射,分别对应于Tm3+的3H4→3F4,3F4→3H6的能级跃迁。 相似文献
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