Bismuth-based erbium-doped fiber as a gain medium for L-band amplification and Brillouin fiber laser

Bismuth-based erbium-doped fiber (Bi-EDF) is demonstrated as an alternative medium for optical amplification and nonlinear applications. The bismuth glass host provides the opportunity to be doped heavily with erbium ions to allow a compact optical amplifier design. The bismuth-based erbium-doped fiber amplifier (Bi-EDFA) is demonstrated to operate at wavelength region from 1570 to 1620 nm using only a 215 cm long of gain medium. The maximum gain of 15.8 dB is obtained at signal wavelength of 1610 nm with the corresponding noise figure of about 6.3 dB. A multi-wavelength laser comb is also demonstrated using a stimulated Brillouin scattering in the 215 cm long Bi-EDF assisted by the 1480 nm pumping. The laser generates more than 40 lines of optical comb with a line spacing of approximately 0.08 at 1612.5 nm region using 152 mW of 1480 nm pump power.     

An all-fiber type Er~(3+)/Yb~(3+) co-doped fiber laser

In this paper, a distributed Bragg reflection (DBR) type Er~(3+)/Yb~(3+) co-doped fiber laser of high output power and high slope efficiency was developed. Its gain medium was a 4.45-m-long Er3+/Yb3+ co-doped fiber. When it was pumped by a 1064-nm Nd:YAG, the linewidth of output laser was measured as 0.072 nm by 3 dB and 0.192 nm by 25 dB at 1552.08 nm. The maximum output power was measured as 69 mW. Its power stability was < 5%, side mode suppression ratio was 59 dB, and the output wavelength stability was ±0.01 nm. The laser had a threshold of 12 mW and a slope efficiency of 22%.     

自调Q、自锁模铒/镱共掺光纤激光器

研究了结构新颖的环形腔铒/镱（Er/Yb）共掺双包层光纤激光器.为了获得高功率激光输出，使用6个激光二极管（LD）同时抽运Er/Yb共掺光纤，采用光纤光栅（FBG）Sagnac环作为波长选择器，得到了中心波长为1548.11 nm、谱线宽度为0.06 nm的窄线宽激光输出；并利用增益光纤作为可饱和吸收体，实现了自调Q、自锁模脉冲输出.当抽运功率为719 mW时，激光器输出自调Q脉冲，脉冲周期为20μs，脉冲宽度为2.8μs，脉冲的平均功率为38.4mW，峰值功率为274.3mW；当抽运功率为3.6 W时，激光器输出自锁模脉冲，脉冲宽度为4ns，平均功率为319 mW，脉冲峰值功率大于10 W，重复频率为7.937 MHz.     

包层泵浦的L波段Er3+/Yb3+共掺光纤激光器

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.     

L波段可调谐线形腔Er/Yb共掺双包层光纤激光器

报道了一种结构简单、工作在L波段、可调谐的线形腔Er/Yb共掺双包层光纤激光器.利用由两段高双折射光纤和两个偏振控制器构成的环镜滤波器对激光器进行调谐，使调谐范围达到34 nm，功率起伏小于±0.2 dB.用976 nm多模LD泵浦Er/Yb共掺双包层光纤产生的ASE作为二次泵源，对未泵浦的一段光纤进行泵浦，使腔内Er/Yb共掺光纤的增益谱移到L波段;多个泵浦源同时对Er/Yb共掺双包层光纤进行侧向泵浦，使激光器输出功率超过了200 mW.     

镱铒共掺硼硅酸盐玻璃可见光波段扎得-奥菲而特理论分析

采用高温烧结工艺制备了多种掺杂浓度的掺铒硼硅酸盐玻璃、镱铒共掺硼硅酸盐玻璃样品.依据扎得-奥菲而特(Judd-Ofelt,J-O)理论计算了三价铒离子扎得-奥菲而特强度参量Ωk(k=2,4,6)和自发辐射寿命、自发辐射跃迁几率、荧光分支比、谱线强度等参量.用麦克库玻(McCumber)理论分析了镱铒共掺硼硅酸盐玻璃铒离子上转换红光(4F9/2→I15/2)、绿光(2>H11/2→I15/2)的受激发射截面.结果表明,随着掺铒硼硅酸盐玻璃中铒离子浓度的增加,扎得-奥菲而特参量Ω2变小;镱铒共掺硼硅酸盐玻璃的Ω2则随掺镱浓度的提高而增大,且高于已有的硅酸盐、氟化物、铋酸盐玻璃的相应值,同时上转换红光和绿光的受激发射截面略有增加.     

Erbium-ytterbium co-doped multi-wavelength double-clad fiber laser around 1612 nm

We report an erbium-ytterbium (Er/Yb) co-doped multi-wavelength laser operation around 1612 nm. The fiber laser was constructed in a figure-of-eight configuration and using a piece of polarization-maintaining (PM) Er/Yb double clad fiber as the gain medium. The oscillation laser lines around 1612 nm could be controlled by carefully adjusting the polarization controllers in the cavity, which might result in single line, dual line or triple line fiber laser operation. The line space was measured about 3.3 nm (±0.2 nm) which was believed to be strongly dependent on the length of the PM Er/Yb co-doped double-clad fiber.     

Er3+-Yb3+共掺磷酸盐玻璃(LGS-L)波导放大器设计

就作者自行研制的Er3 + Yb3 + 共掺磷酸盐玻璃 (LGS L) ,用重叠积分方法进行放大器设计。在Er3 + 、Yb3 + 掺杂浓度分别为 1.5 1× 10 2 6ions/m3 、19.1× 10 2 6ions/m3 的情况下可获得 2 .6dB/cm的增益 ;Er3 + 掺杂浓度为2× 10 2 6ions/m3 时 ,在 4cm的器件上可获得超过 15dB的增益。此外 ,讨论了信号光和抽运光光场强度的横向分布与Er3 + 、Yb3 + 横向掺杂浓度分布之间的重叠对放大器增益的影响 ,放大器的最佳长度 ,以及在 980nm抽运下 ,Yb3 + 、Er3 + 掺杂浓度比对放大器增益的影响。     

A Flat-Gain Double-Pass Amplifier with New Hafnia-Bismuth-Erbium Codoped Fiber

An efficient and compact double-pass optical fiber amplifier is demonstrated using a newly developed hafnia bismuth erbium co-doped fiber(HBEDF) as a gain medium. The HBEDF is fabricated using a modified chemical vapor deposition in conjunction with solution doping. The fiber has an erbium ion concentration of 12500 ppm.At the optimum length of 0.5 m, the HBEDF amplifier(HBEDFA) achieves a flat gain of 26 d B with a gain variation of less than 1.5 d B within a wavelength region from 1530 to 1560 nm when the input signal and pump power are fixed at-30 d Bm and 140 m W, respectively. On the other hand, at the input signal power of-10 d Bm,the HBEDFA also achieves a flat gain of 14.2 d B with a gain variation of less than 2.5 d B within a wide wavelength region from 1525 to 1570 nm. Compared with the conventional zirconia erbium co-doped fiber based amplifier,the proposed HBEDFA obtains a more efficient gain and lower noise figure. For an input signal of-30 d Bm, the gain improvements of 6.2 d B and 4.8 d B are obtained at 1525 nm and 1540 nm, respectively.     

Er-Yb共掺双包层光纤的研制

报道了溶液掺杂法制备Er-Yb共掺双包层光纤的技术.采用改进的化学汽相沉积研制工艺,制作了SiO2-P2O5-F的光纤阻挡层和SiO2-GeO2-P2O5的疏松芯层,利用疏松芯层在YbCl3、ErCl3溶液中的浸泡吸收作用,成功研制出Er、Yb离子浓度比分别为1∶13和1∶8两个光纤样品,其中样品2在976 nm泵浦波长处的有效吸收系数最大达到2 dB/m,分析和讨论了光纤的损耗谱和荧光特性.     

Er3+单掺和Er3+/Yb3+双掺铋硼酸盐玻璃的研究

用高温熔融法制备了Er^3 单掺和Er^3 /Yb^3 双掺铋硼酸盐玻璃样品，测量了上述玻璃样品的吸收光谱，荧光光谱，荧光寿命以及红外透过率。对高浓度掺杂Er^3 的铋硼酸盐玻璃中的浓度猝灭现象作出了解释。分析了Er^3 ／Yb^3 双掺铋硼酸盐玻璃样品中Yb^3 离子对Er^3 离子的敏化过程。研究发现Er^3 ／Yb^3 双掺铋硼酸盐玻璃在1．5～1．6μm波段有宽达81nm的荧光半峰全宽。实验还发现在熔制过程中通入氧气对其荧光寿命和红外透过率都有明显的提高。由于该玻璃材料表现出较好的物化性能。因此该材料可望成为宽带光纤放大器的适宜的基质材料。     

高浓度镱铒共掺磷酸盐光纤放大器增益特性

在忽略高能级的自发辐射和光纤损耗的情况下，利用速率方程和传输方程理论研究了高浓度Er³⁺/Yb³⁺共掺磷酸盐玻璃光纤放大器的增益特性，讨论了Er³⁺浓度、Yb³⁺浓度、抽运光功率、信号光功率、光纤长度对放大器增益的影响，并与单掺铒光纤放大器进行了比较.由于Yb³⁺的敏化作用降低了铒离子的团簇效应，减少了离子间相互作用，共掺光纤的增益和效率明显高于单掺光纤.数值计算表明，3.2cm长Er³⁺/Yb³⁺共掺光纤在980nm的20dBm(100mW)抽运功率下，1532nm处的增益可达10dB. 关键词： 镱铒共掺光纤放大器 速率方程 传输方程 高浓度     

Performance of optical amplifier employing silica host magnesium-aluminum-germanium co-doped erbium-doped fiber

Two silica host magnesium(Mg)-aluminum(Al)-germanium(Ge) co-doped erbium-doped fibers (EDFs)have been fabricated, which have different Mg concentrations. The concentration of all the compositions in the preform is measured through electronics probe micro analysis (EPMA). The maximum Mg concentrations of fibers A and B are 3.98 and 1.28 mol%, respectively. The performance characteristics including absorption spectrum and gain are measured and analyzed. The absorption coefficients of fibers A and B are 13.3 and 14.3 dB/m respectively at wavelength of 1532 nm. The max gains of these two erbium-doped fiber amplifiers (EDFAs) are 30.1 and 35.9 dB with input signal power of -30 dBm and pump power of 100 mW at 980 nm. Fiber B with maximum Mg concentration 1.28 mol% has better performance than fiber A. Fiber B has high absorption coefficient and high gain characteristics. The optimum fiber B length of C-band EDFA is 7 m and that of L-Band EDFA is about 30 m, which is much shorter than standard commercial EDFAs. The result of experiments showed that a few Mg added to silica host EDF can increase the concentration of erbium ions, which will shorten the EDF length much, but not degrade the performance characteristics.     

基于高双折射光纤布拉格光栅的自动增益控制掺铒光纤放大器

掺铒光纤非均匀展宽引起的空间烧孔现象导致单波长激光并不能完全控制放大器增益,提出了一种新颖的自动增益控制掺铒光纤放大器的结构:即采用高双折射光纤布拉格光栅产生抽运光,其写制光栅的波峰对应的波长分别为1549.3 nm和1549.83 nm,波长间隔为0.53 nm。通过调整偏振控制器,就实现了单激光或双激光的增益控制。这种设计增益控制范围为40 nm(1530~1570 nm),当输入功率在-40~-15 dBm的动态范围内,双激光增益控制的掺铒光纤放大器的平均增益和噪声系数分别约为22.22 dB和8.69 dB,而它们的漂移分别被钳制在0.69 dB和1.51 dB。系统性能测试表明:双激光控制掺饵光纤放大器在稳定性方面比单激光有着明显的优势。     

单偏振控制器环形腔光纤激光器实验研究

理论分析了非线性偏振旋转环形腔作为类饱和可吸收体获得脉冲的物理机理。在光纤环形腔结构中,采用单个偏振控制器实现了非线性偏振旋转锁模,直接获得了脉冲宽度为131 fs的超短脉冲输出。实验中,采用性能稳定的976 nm半导体二极管激光器作为抽运源,使用高掺杂浓度的Er3 光纤为增益介质,通过调节偏振控制器,获得了光谱谱宽(3 dB带宽处)为23.5 nm的稳定锁模脉冲输出。脉冲中心波长为1535.9 nm,平均功率为5.91 mW,脉冲重复率为11.20 MHz。     

Multi-wavelength erbium-doped fiber laser using four-wave mixing effect in doped fiber

We demonstrate a multi-wavelength erbium-doped fiber laser (EDFL) using erbium gain and four-wave mixing (FWM) effect in a piece of erbium-doped fiber (EDF) with high erbium ion concentration. The EDF has a pump absorption rate of 24.6 dB/m at 979 nm and is bi-directionally pumped by 980-nm laser diodes. FWM effect redistributes the energy of different oscillating lines and causes multi-wavelength operation. The laser generates more than 22 lines of optical comb with a line spacing of approximately 0.10 nm at the 1569-nm region using only 1.5-m-long EDF.     

Tm3+/Ho3+共掺碲酸盐微结构光纤激光器

用棒管法拉制了Tm³⁺/Ho³⁺掺杂的碲酸盐微结构光纤,并获得了2 μm的激光输出。以1 560 nm的Er³⁺掺杂石英光纤激光器作为泵浦源,在22 cm长的微结构光纤中,得到了最大功率为8.34 mW、波长为2 065 nm的连续激光输出,泵浦光功率为507 mW,斜率效率为2.97%。研究结果表明,Tm³⁺/Ho³⁺共掺碲酸盐微结构光纤是一种用于研制2 μm激光器的理想材料。     

Medium power single-mode single-wavelength fiber laser

Medium-power, single-mode, single-wavelength fiber laser working at room temperature using a polarization-maintaining erbium-ytterbium co-doped fiber as the gain medium, and an un-pumped elliptical core erbium-doped fiber as a saturable absorber to reduce linewidth and mode hopping of the lasing wavelength is reported. The effects of length, erbium ion concentration, and polarization-maintaining property of the saturable absorber were explored. The output power of the laser was more than 100 mW and the lasing line was stable for more than 3 h with an intensity fluctuation of less than 0.2 dB. The laser linewidth (FWHM = Full width at half maximum) was 7.5 MHz and the signal to noise ratio was more than 50 dB. The output of the laser was measured using an optical spectrum analyzer (OSA) of resolution 1.25 GHz and a scanning Fabry-Perot spectrum analyzer (SFPSA) of resolution 6.7 MHz.     

利用频谱组束获取双光谱光源的实验研究

 针对激光多光谱探测对多色激光光源的需求,提出利用外腔频谱组束技术获取多光谱激光探测光源的方法。报道了外腔2个大模面积双包层Er3+/Yb3+共掺光纤激光器频谱组束的实验结果,获得了一种3dB线宽分别为29.3nm和11.52nm的可调谐双光谱激光探测光源。实验结果和理论分析表明：外腔频谱组束技术是一种获得多光谱激光光源的可行方法。     

Er~(3+)/Eu~(3+)及Yb~(3+)/Er~(3+)/Eu~(3+)共掺杂硼硅酸盐玻璃的上转换发光分析

采用高温固相烧结法制备了Er3+/Eu3+共掺杂和Yb3+/Er3+/Eu3+共掺杂系列硼硅酸盐玻璃样品。在978 nm半导体激光器抽运下,测量了样品的光致发光谱,分析了上转换机制。结果表明:随着Er3+浓度的增加,Eu3+的595 nm光谱强度增强;Eu3+的692 nm光谱强度随Yb3+浓度增加而增强,并明显强于595 nm光谱。Er3+/Eu3+、Yb3+/Eu3+之间的能量传递和合作上转换等机制导致Eu3+离子上转换发射。