脊形掺铒Al2O3光波导放大器级联特性的模拟计算

利用有限元法分析了脊形掺铒Al₂O₃光波导放大器内信号光和抽运光的场模式分布、速率方程求解铒离子五能级系统的粒子数分布.数值模拟了光波导净增益与信号光功率的关系和多个放大器级联的净增益特性.结果表明：级联系统存在着净增益亏损.低掺铒浓度的光波导作前级放大器的组合方式,级联系统总净增益最大.     

阶跃掺杂Er∶Al2O3光波导放大器增益特性数值模拟

构建了纵向阶跃非均匀掺杂的掺铒Al2O3光波导放大器理论模型,利用有限元法、速率方程和传输方程,数值模拟了放大器的净增益特性.计算结果表明：阶跃掺杂掺铒Al2O3光波导放大器提高了抽运效率,净增益和信号光输出功率比优化后的均匀掺杂光波导放大器分别提高了9.2%和90.5%,长度却缩短了16.9%.     

阶跃掺杂Er∶Al2O3光波导放大器增益特性数值模拟

构建了纵向阶跃非均匀掺杂的掺铒Al2O3光波导放大器理论模型,利用有限元法、速率方程和传输方程,数值模拟了放大器的净增益特性.计算结果表明:阶跃掺杂掺铒Al2O3光波导放大器提高了抽运效率,净增益和信号光输出功率比优化后的均匀掺杂光波导放大器分别提高了9.2%和90.5%,长度却缩短了16.9%.     

阶跃掺杂Er∶Al_2O_3光波导放大器增益特性数值模拟

构建了纵向阶跃非均匀掺杂的掺铒Al2O3光波导放大器理论模型,利用有限元法、速率方程和传输方程,数值模拟了放大器的净增益特性·计算结果表明阶跃掺杂掺铒Al2O3光波导放大器提高了抽运效率,净增益和信号光输出功率比优化后的均匀掺杂光波导放大器分别提高了9.2%和90.5%,长度却缩短了16.9%.     

LaF3:Er,Yb纳米颗粒掺杂有机/无机杂化材料制备光波导放大器及特性研究

采用LaF3:Er,Yb纳米颗粒掺杂有机/无机杂化材料作为有源材料,制备了掩埋条形结构光波导放大器,研究了放大器在室温下的增益特性和波导中的频率上转换现象. 当抽运功率60 mW时,波导中明显可见绿色上转换发光,观测到Er3+从2H9/2,2H11/2,4S3/2,4F9/2到基态4I15/2跃迁分别对应的4个波长分别为405nm, 520nm, 544nm和650nm的发射峰,分析了其产生机理. 当输入信号光0.6mW,抽运功率160 mW时,在1535nm波长处获得1.5 dB/cm的相对增益.     

Er3+,Yb3+共掺磷酸盐玻璃沟道波导放大器

在自行研制的Er3 ，Yb3 共掺磷酸盐玻璃基质上用离子交换方法制作出沟导光波导放大器。在110mW的抽运功率下(抽运光波长为980nm)，在1．8cm长的器件上获得了3．8dB的小信号(信号光波长为1．55μm)增益，单位长度上的增益为2．1dB／cm。     

抽运光与信号光的光强重叠因子和掺铒玻璃波导放大器的增益特性

在掺铒玻璃波导放大器（EDWA）的三能级速率-传输方程中,考虑两次离子交换工艺中波导掩模窗口宽度w不同所导致的抽运光、信号光模场与光强分布的不同,讨论不同w对EDWA增益特性的影响,得到光强分布的数值解.引入描述波导中抽运光和信号光的归一化光强重叠因子,对EDWA的传统近似解提出修正,得到了修正解,使其更加接近光强分布的数值解.模拟结果表明,在条波导长度为4 cm、抽运光波长为980 nm、功率为80 mW、信号光波长为1534 nm、功率为-10 dBm条件下,不同w所导致EDWA的增益差别可达297 dB.修正解的结果比传统近似解更加接近光强分布的数值解.修正解对于EDWA的理论研究、器件设计具有指导作用. 关键词： 集成光学 掺铒玻璃波导放大器 重叠积分因子 增益     

铒镱共掺微环谐振器的放大特性分析

对铒镱共掺微环谐振器的放大特性进行了理论分析,给出了器件的传递函数和功率增益的公式.在抽运光波长为0.98 μm、信号光中心工作波长为1.55μm的情况下,分析了抽运光功率、信号光功率、铒镱掺杂浓度、微环与信道间的振幅耦合比率对放大器放大特性的影响,给出了上下信道的传输光谱,并对其结构进行了优化设计.模拟结果表明,与同等长度的直条形铒镱共掺波导放大器相比,该器件町获得更高的信号光增益,选取Ppo=8 mW,Pso=36.5μw,NEr=1×1026m-3,NYb=3×1027m-3时,该器件可容易地获得11.6 dB以上共至高达60 dB的信号光功率增益.这种强放大功能的铒镱共掺微环谐振型放大器,将更有利于器件在尺寸上的小型化、集成化.     

掺铒光波导放大器的速率方程分析

用重合积分的方法 ,分析了描述掺铒光波导放大器 (EDWA)的速率方程 ,得到了 980nm波段抽运的掺铒光波导放大器增益的隐式解析解 ,在此基础上得到了抽运阈值功率的解析表达式。计算了掺铒平面光波导放大器中的光场与铒掺杂浓度分布的重叠因子。讨论了铒掺杂浓度对抽运阈值功率的影响及抽运功率对增益的影响。     

制备工艺对掺杂NaYF4:Er3+,Yb3+发光纳米晶的聚合物光波导放大器性能的影响

制备了NaYF₄：Er³⁺,Yb³⁺纳米晶,表征了纳米晶的形貌,通过物理掺杂的方式将纳米粒子掺杂到SU-8中作为光波导放大器的芯层材料,优化了波导放大器的尺寸,利用旋涂、刻蚀等工艺,在二氧化硅衬底上制备了光波导放大器。实验中用光漂白法和湿法刻蚀两种方法制备光波导放大器,分别给出了两种方法制备的器件的结构、工艺流程、光场模拟结果,并对两种方法制备的器件的放大特性进行了测试。测试结果表明,当980 nm波长的泵浦光功率为241 mW且1 550 nm波长的信号光功率为0.1 mW时,使用湿法刻蚀法制备的放大器得到2.7 dB的相对增益。当980 nm波长的泵浦光功率为235 mW且1 550 nm波长的信号光功率为0.1 mW时,使用光漂白法制备的放大器得到4.5 dB的相对增益。根据以上测试结果,分析了两种工艺对器件性能的影响。     

掺铒光纤放大器的增益特性

采用980nm无铝InGaAs/InGAsP/InGaP高功率量子阱激光器泵浦掺铒光纤放大器。在泵浦功率为20mW时,增益为33dB,最大增益系数6．7dB/mW,饱和输出功率为6dBm,并给出掺铒光纤长度和泵浦功率与增益特性的关系。以及输出功率与增益特性的关系。     

被动锁模Yb3+光纤环形腔激光器的研究

 采用974 nm半导体激光器作为泵浦源，超高掺杂Yb³⁺光纤作为增益介质，利用光纤的非线性偏振旋转效应，得到稳定的ps量级锁模光脉冲。泵浦功率220 mW时，激光器锁模阈值功率150 mW，输出功率26 mW，锁模光脉冲中心波长1 046 nm，3 dB带宽6.01 nm，20 dB带宽16 nm，脉宽22 ps，重复频率20 MHz。与同类光纤激光器相比，该激光器输出功率高，具有更好的稳定性。     

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.     

基于KMnF_3∶Yb~(3+),Er~(3+)纳米晶的红光聚合物平面光波导放大器

制作了基于KMnF_3∶Yb~(3+),Er~(3+)纳米晶材料的工作波长655 nm的聚合物平面光波导放大器。材料的吸收光谱表明,KMnF_3∶Yb~(3+),Er~(3+)纳米晶在980 nm附近有很强的吸收。在980 nm激光的激发下,由于Er~(3+)和Mn2+能级之间的能量传递,KMnF_3∶Yb~(3+),Er~(3+)纳米晶产生了很强的红色上转换发光。根据KMnF_3∶Yb~(3+),Er~(3+)纳米粒子的发光特性,制备了KMnF_3∶Yb~(3+),Er~(3+)NCs-PMMA复合材料,用其作为芯层设计了掩埋形结构光波导放大器,利用传统的半导体工艺完成器件制备。器件测试结果表明,当655 nm信号光功率为0.1 m W、980 nm泵浦功率为260 m W时,器件获得了2.7 d B的相对增益。     

An effective numerical method for gain profile optimizations of multi pumped fiber Raman amplifiers

In this paper, we have solved propagation equations of multi-pump fiber Raman amplifier using Runge–Kutta (RK 4th order) numerical method and pump power evolutions along with the fiber length. They are used to calculate the net gain and gain ripple by varying the input signals powers for different fiber lengths. The pump powers are optimized by genetic algorithm and resulting net gain and gain ripple are reported graphically as well as in tabular form. The optimum minimum gain ripple is 0.26 dB for 1 mW input signal powers for 50 km fiber length. By increasing the fiber length gain ripple increases to 0.5 dB for 0.1 mW input signal power. In comparison to other methods reported in the literature, our method is simple to implement and efficient for numerical design of Raman amplification in optical communication systems.     

Optimization of the power ratios of the bidirectional pumping at two wavelengths for erbium-doped fiber amplifiers

The gain and noise factor spectra of erbium-doped fiber amplifiers with pumped according to a copropagating three-level scheme and according to a counterpropagating quasi-two-level scheme in the regime of unsaturated gain in the C band have been simulated numerically. It has been shown that, at the total pump power up to 30 mW and at the optimized power ratio of the copropagating and counterpropagating pumps, the inhomogeneity of the gain in the C band does not exceed 0.25 dB at the noise factor of 4.2–4.7 dB.     

Systematic investigation of the avalanche effect in highly thulium-doped fiber amplifiers

The avalanche energy transfer in highly thulium doped fiber amplifiers (TDFA) pumped at 1056 nm with laser diodes was investigated. Amplified spontaneous emission (ASE) at 800 nm and 1470 nm as well as the remaining pump power were measured as function of the pump power to explain the efficiency of the energy transfer between thulium ions. As proof of our theory, fiber amplifiers based on self-made fluoride fibers doped with 2000 and 5000 ppm thulium were realized and their gain and noise figure was measured. A gain of more than 25 dB and a noise figure of less than 4 dB was achieved at a pump power of 210 mW in a TDFA using the 5000 ppm thulium fiber, whereas a gain maximum of only 5.6 dB was observed with the 2000 ppm TDF. These investigations are of special importance since until now almost all TDFAs have used 2000 ppm fibers. PACS 83.80.Ab; 32.80.Bx; 42.65.Yj     

1 064 nm波长双向泵浦的S波段掺铥石英光纤放大器

研究了1 064 nm波长双向泵浦的掺铥石英光纤放大器（TDSFA）,测量了信号开关增益随泵浦功率和信号波长的变化情况.在最大入纤功率1 400 mW泵浦下,放大器在1 485~1 517 nm的较宽范围内具有放大能力,最大增益3.76 dB.分析表明,弱的基态吸收和强的激发态吸收限制了放大器增益的进一步提高,表明上转换泵浦的TDSFA是可行的.     

Raman amplification characteristics of As2Se3 photonic crystal fibers

We present the dispersion and Raman amplification characteristics of As2Se3 photonic crystal fibers (PCFs). We compare the gain characteristics with conventional As2Se3 fibers and find that the Raman gain efficiency in PCFs can be improved by a factor of more than 4. This allows us to either use a small length of the fiber or to use the low pump power to attain similar gain characteristics. Numerical simulations reveal that a peak gain of 10 dB can be achieved in a 1.1 m long PCF when it is pumped at 1.5 microm in wavelength with an input power of 500 mW.     

Amplification effect on stimulated Brillouin scattering in the S-band forward G652 fiber Raman amplifier

The amplification effects on forward and backward stimulated Brillouin scattering (SBS) lines in the forward pumped S-band distributed G652 fiber Raman amplifier (FRA) have been studied. There is a pump threshold power of Stokes backward stimulated Brillouin scattering (B-SBS) line in the forward pumped G652 FRA, it is about 1 mW. The Stokes B-SBS lines are amplified by FRA and fiber Brillouin Brillouin gain. In experimental work, the saturation gain of the first order Stokes backward SBS line is about 58 dB and the saturation gain of 25-km G652 forward FRA is about 25 dB, so the gain of FBA is about 33 dB. The forward stimulated Brillouin scattering (F-SBS) is generated and amplified in S-band G652 FRA. The stimulated threshold powers of the forward first order Stokes SBS (SB1-), second order Stokes SBS (SB2-), and third order SBS (SB3-) in the forward pumped FRA are 2.3, 1.6, and 1.6 mW,respectively. In experimental work, the saturation gains of SB1-, SB2-, and SB3- are about 38, 62, and 60 dB, respectively. The saturation Raman gain of 25-km G652 forward FRA is about 8.8 dB, so the Brillouin gains of SB1-, SB2-, and SB3- are about 29.2, 53.2, and 51.2 dB, respectively. The forward and backward cascaded SBS lines have been observed.