基于后向ASE抽运的L-波段掺铒光纤放大器

利用后向ASE抽运一段未抽运光纤和一段不完全抽运光纤两种结构 ,实现了EDFA自发辐射谱向长波方向移动 ,分别得到了 3dB带宽为 5 6 3nm和 4 7 6nm的L 波段自发辐射谱 ,对 1 5 75nm输入信号 (强度为 - 3 0dBm)的增益分别为 3 5dB和 9 2dB     

一种新颖的多波长环形腔掺铒光纤激光器

提出了一种结构新颖的多波长环形腔掺铒光纤激光器 ,在其结构中采用了一种新型梳状滤波器 ,该滤波器由一个光纤光栅非对称写在一个Sagnac环中来实现 ,具有设计简单、易于制作、成本低和插入损耗小等优点。实验中得到了非常稳定的三波长和双波长激光输出 ,线宽均小于 0 0 6nm ,输出波长间隔分别为 0 34nm和 0 5nm ,输出功率差异分别在 2dB和 0 4dB内 ,消光比分别为～ 40dB和～ 5 0dB。     

一种具有平顶陡边响应的新型谐振腔增强型(RCE)光电探测器的理论分析及模拟

提出了一种适用于波分复用系统的具有平顶陡边响应的新型谐振腔增强型 (RCE)光电探测器结构 ,模拟得到了量子效率从峰值下降 0 5dB的线宽 1 8nm ,10dB的线宽 5 6nm ,2 0dB的线宽 10 4nm ,量子效率峰值99 7%,几乎没有凹陷的响应曲线。     

一种高稳定DBR 型掺铒光纤激光器研究

研制了一种高功率高边模抑制比及高波长稳定性的DBR 型掺铒光纤激光器。该激光 器使用980nm LD 作为泵浦源,并使用长度为2. 75m 的高掺杂浓度的掺饵光纤作为增益介质,在1. 55μm 波段获得了3dB 线宽为0. 2nm ,25dB 线宽为0. 4nm 的激光输出。最大输出光功率25mW ,输出功率稳定性±0. 01dB ,边模抑制比60dB ,波长稳定性0. 01dB (受光功率计精度的限制) ,阈值泵浦光功率8. 6mW ,斜率效率21. 7 %。     

1.3μm高增益偏振无关应变量子阱半导体光放大器

采用低压金属有机化学气相外延法 (LP MOVPE)生长并制作了 1 3μm脊型波导结构偏振无关半导体光放大器 (SOA) ,有源区为基于四个压应变量子阱和三个张应变量子阱交替生长的混合应变量子阱 (4C3T)结构 ,压应变阱宽为 6nm ,应变量 1 0 % ,张应变阱宽为 11nm ,应变量 - 0 95 % ;器件制作成 7°斜腔结构以有效抑制腔面反射。半导体光放大器腔面蒸镀Ti3 O5/Al2 O3 减反 (AR)膜以进一步降低腔面剩余反射率至 3× 10 -4以下 ;在 2 0 0mA驱动电流下 ,光放大器放大的自发辐射 (ASE)谱的 3dB带宽大于 5 0nm ,光谱波动小于 0 4dB ,半导体光放大器管芯的小信号增益近 30dB ,在 12 80～ 1340nm波长范围内偏振灵敏度小于 0 6dB ,饱和输出功率大于 10dBm ,噪声指数 (NF)为 7 5dB。     

一种新型宽带EDFA及其实验研究

文章提出了一种基于三端口增益平坦滤波器、且在拓扑结构上不同于以往并行或串行结构的掺铒光纤放大器（EDFA）的新结构。理论模拟显示，同常规的并行结构EDFA相比，该新型结构在保证C波段EDFA性能的同时亦可将L波段掺铒光纤（EDF）用量减少48％以上，改善L波段泵浦效率55％以上。实验中，我们在C波段使用两只输出功率分别为106．9和109．6mW的980nm泵浦激光器，两段EDF的长度分别为8．5和9．6m，在L波段我们仅用1只80mW的1480nm泵浦激光器，EDF长度为19．8m。试验结果显示，在C＋L波段内得到的信号增益〉23dB，增益平坦度〈0．6dB，噪声指数在C和L波段内分别〈4．4dB和5.6dB。     

四信道波分复用器／解复用器

GigabitOptics公司研制的MicroMux型疏集波分复用器 /解复用器 ( 9mm× 9.2mm× 6mm)适用于光通信网络子系统中的线卡集成。该装置能组合或分离 4个信道的传输信号 ,适用于城域核心网、城域接入网和企业疏集波分复用系统 ;多波长 30 0针脉冲转发机、GBIC和Xenpak无线电收发机。该装置符合国际电信联盟ITU G694 2规定。主要性能为 :标准信道间隔 2 0nm、波长范围 1 45 0～ 1 630nm、插损≤ 2dB、回程损耗≥ 45dB、偏振依赖损耗≤ 0 .1 5dB。 (No .1 6)四信道波分复用器/解复用器…     

Nd3+∶Y0.5Gd0.5VO4晶体光谱特性

测量了 0 8at. %Nd3 + ∶Y0 .5Gd0 .5VO4的吸收光谱和荧光发射谱 ,光谱显示该晶体在 80 8 5nm有很强的偏振光吸收峰 ,且π偏振光 (E∥C)吸收远强于σ偏振光 (E ⊥C) 吸收 ,半高宽度分别为 4 5nm和 12nm ,吸收截面分别为 19 6 9× 10 -2 0 cm2 和 6 4 1× 10 -2 0 cm2 ;其荧光发射 (4F3 /2 → 4I11/2 跃迁 )峰值波长在 10 6 4nm ,半高宽度为 3 7nm ;4F3 /2 → 4I11/2 跃迁的荧光寿命为 110 μs;光谱特性表明Nd3 + ∶Y0 .5Gd0 .5VO4晶体是潜在的高效率激光晶体材料     

高信噪比可调谐环形掺铒光纤激光器的研究

报道用 980nm半导体激光器泵浦的仅用 3m高掺铒光纤连续可调谐环形光纤激光器的一些实验研究结果。可调谐谱宽可达 3 0nm(从 1.5 3 μm到 1.5 6μm) ,2 5dB带宽 <0 .4nm ,边模抑制比 >5 5dB。最大输出光功率 3 3mW ,功率稳定性优于± 0 .0 2dB。阈值泵浦功率 8.6mW ,斜率效率达 3 6.67%。     

一种实用化的高功率低噪声波长连续可调光纤激光器

报道了一种基于光纤光栅 (FBG)的高功率可调谐环形腔掺铒光纤激光器。该激光器由 980nm激光二极管(LD)抽运 ,在 15 6 2nm波段获得了线宽小于 0 0 4nm的激光输出 ,调谐范围可达 4 6nm ,输出波长复现性误差小于 0 0 8nm。由于铒光纤选择了最佳长度 ,并在光纤环路中引入两个隔离器抑制噪声 ,提高了信噪比 ,激光器输出的最大功率可达 4 2 8mW ,此时功率稳定性为± 0 0 3dB ,斜率效率为 7 3%。     

Polarization-independent tunable wavelength-selective filter usinga liquid crystal

The authors demonstrate a polarization-independent liquid crystal Fabry-Perot interferometer. An input light beam was split into two orthogonal polarized beams by a polarization beam splitter and prism and the polarization of one beam was rotated 90° by a half-wave plate. These two beams were filtered through different points of the filter and recombined. Two transmission peaks corresponding to these beams usually appeared. However, there were some regions where the two beams were superimposed. At these regions, the filter had a tuning range of over 50 nm with a band pass of 0.4-0.5 nm and a low fiber-to-fiber loss of 3 dB. At the regions where two peaks appeared, the two peaks could be superimposed by applying different voltages     

激光合成波长纳米测量干涉仪的非线性误差分析

描述了激光合成波长纳米测量干涉仪的测量原理,分析了非线性误差对该干涉仪的影响,得出了由偏振光非正交、椭偏化和光学元件偏振非正交及椭偏化等对该干涉仪造成的非线性误差为偏振态误差的二阶或高阶小量。进行了激光合成波长纳米测量干涉仪和激光外差干涉仪的对比实验,结果表明激光合成波长纳米测量干涉仪的最大误差为2.1nm,优于激光外差干涉仪的最大误差7.5nm,验证了激光合成波长纳米测量干涉仪的优越性。     

双矩形纤芯光子晶体光纤偏振分束器

基于双折射效应设计了一种新颖的纤芯为椭圆空气孔,包层为圆形空气孔的矩形双芯光子晶体光纤偏振分束器。用半矢量光束传播法(BPM)数值模拟了基模情形下该偏振分束器的性能,结果表明:在工作波长为1.55μm,光纤长度为1659μm时,两个纤芯在X、Y方向偏振光的隔离度分别达到了-41.3 dB和-39.1 dB,隔离度小于-10 dB的带宽超过了80 nm,达到了良好的偏振分束性能。同时,模拟了实际加工误差对所设计的偏振分束器的影响,得出在1.55μm的工作波长下,误差达到±7%时,隔离度仍能小于-10 dB,具有较高的实际应用价值。     

一种基于多模干涉耦合器的集成光开关研制

设计并制作了一种采用InP/InGaAsP材料的2×2基于多模干涉(MMI)器的Mach-Zehnder干涉仪(MZI)光开关,用三维有限差分束传播法(3D-BPM)对器件进行了优化设计与模拟分析。开关端口设计为单模波导且对偏振不敏感,采用电流注入调制相移区折射率,当折射率的改变引起π相位差时实现开关状态转换。测试结果表明,当注入电流达到43 mA时光信号从交叉端口交换到直通端口,开和关状态的串扰分别为-19.2 dB和-14.3 dB。     

Polarization-Insensitive Operation of Lithium Niobate Mach–Zehnder Interferometer With Silica PLC-Based Polarization Diversity Circuit

We demonstrate the polarization-insensitive operation of a Mach-Zehnder interferometer (MZI)-based lithium niobate switch with a silica waveguide polarization beam splitter. The splitter is composed of an MZI with a half wave plate installed in one arm, and exhibits a polarization extinction ratio of more than 15 dB. The switch functions for both polarizations with an extinction ratio of more than 20 dB, a polarization-dependent loss of 0.1 dB and a switching speed of 40 ps.     

High-isolation polarization-independent quasi-optical circulator

A polarization-independent quasi-optical circulator having high isolation over a wide wavelength range is reported. The proposed quasi-circulator is composed of two polarization beam splitters, two pentagonal prisms, two nonreciprocal rotators, and two walkoff polarizing beam splitters. Its structure is very simple. A three-port quasi-circulator has been fabricated with single-mode fibers. Its insertion loss and isolation have been measured to be ⩽1.7 and ⩾48.6 dB, respectively, at the nominal wavelength of 1.3 μm. A loss ratio of over 47.0 dB has been realized. The wavelength range over a 50-dB isolation between two fibers was measured to be about 50 nm     

基于偏振合束的相移雅满剪切干涉仪

相移雅满横向剪切干涉仪非常适合于达到衍射极限的光束的波面检测。为了改进现有的在两路剪切光束中直接插入起偏器的相移雅满剪切干涉仪,提出了一种基于偏振合束的相移雅满剪切干涉仪。该剪切干涉仪利用雅满平板前后表面的反射进行分束并形成两路干涉光束,两路干涉光束分别通过剪切平板后偏振合束并进行偏振移相。它保持了常规雅满剪切干涉仪的光路结构,提高了剪切干涉图的对比度,不再存在插入起偏器引入测量误差的问题。构建了改进前、后的两种相移雅满双剪切干涉仪,并进行了相应的对比实验,实验结果很好地验证了基于偏振合束的相移雅满剪切干涉仪的实用性。     

A switchable dual-wavelength erbium-doped fiber laser based on Sagnac loop inserted with two FBGs

A novel switchable dual-wavelength erbium-doped fiber （EDF） laser is demonstrated. The wavelength selection ele- ment consists of two fiber Bragg gratings （FBGs）, a polarization controller （PC） and a 3 dB coupler forming a Sagnac loop inserted with two FBGs. We study the effect of coupling ratio on filtering performance in this paper. By adjusting PC, we can change the wavelength-dependent loss, and then using nonlinear polarization rotation effect to suppress the mode competition caused by the homogeneous broadening of EDF, we obtain single- and double-wavelength laser outputs. At room temperature, under 200 mW pump power, dual-wavelength laser is achieved, and the center wave- lengths are 1545.34 nm and 1548.20 nm, respectively. The peak power values are -13.36 dBm and -14.58 dBm, and side mode suppression ratios （SMSRs） are 41.10 dB and 39.88 dB, respectively. Within two hours, the maximum fluctuation of peak power is less than 0.7 dB, which shows that the demonstrated fiber laser is stable. Moreover, by adjusting PC, singel-wavelength laser output is obtained, the peak power is -6.27 dBm or -5.45 dBm, and SMSR is 40.03 dB or 39.96 dB at 1545.34 nm or 1548.20 nm, respectively.     

基于内嵌FBG的Sagnac环的双波长光纤激光器

提出了一种内嵌光纤Bragg光栅(FBG)对的Sagnac环结构双波长掺铒光纤(EDF)环形激光器。对内嵌FBG对的Sagnac环的滤波特性进行了理论分析,实验获得了输出波长分别为1 554.92nm和1 555.2nm的稳定双波长光纤激光,边模抑制比约为65dB,功率稳定性优于0.2dB,波长稳定性优于0.02nm。     

A tunable polarization-independent liquid-crystal Fabry-Perotinterferometer filter

The authors propose a simple structure for a tunable polarization-independent wavelength-selective filter. This successfully fabricated filter consists of a liquid crystal Fabry-Perot interferometer, a γ/4 plate, and a mirror. The input light is divided into a transmitted light and a reflected light. The polarization of this reflected light is rotated 90° by the γ/4 plate and the mirror and then this light is input again into the filter. The bandwidth is 0.48 nm and the tuning range is 50 nm. Fiber-to-fiber loss is approximately 3.9 dB and polarization dependence of the loss is approximately 0.3 dB