用于1310nm波长光放大器的掺P_r~(3+)氟化物光纤设计模型

用Ｐ３＋ｒ 离子四能级系统的信号模型研究掺Ｐ３＋ｒ 氟化物光纤放大器的信号特性。模型考虑ＬＰ０１模在阶跃型折射率分布单模光纤中的径向分布以获得激励辐射、信号激发态吸收和泵浦吸收截面，发现最佳截止波长为７５０ｎｍ 且与光纤的数值孔径和输入泵浦功率无关，而数值孔径应设计得尽可能大     

Wideband Hybrid Fiber Amplifier Using Er‐Doped Fiber and Raman Medium

In this paper, we report the experimental results of a hybrid wideband fiber amplifier. The amplifying medium is a concatenated hybrid fiber consisting of Er‐doped fiber (EDF) and dispersion compensating fiber (DCF). The gain mechanisms are based on stimulated emission in the EDF and stimulated Raman scattering (SRS) in the DCF. Since we simultaneously use optical amplification by the two processes, the gain bandwidth is easily expanded over 105 nm by a two‐tone pumping scheme. Using an experimental setup constructed with a hybrid structure of EDF‐DCF‐EDF, we analyzed the spectral behavior of amplified spontaneous emission for pumping powers. We achieved an optical gain of over 20 dB in the wavelength range from 1,500 to 1,600 nm under optimized pumping conditions to make the spectral gain shape flat.     

Pr3+‐ and Pr3+/Er3+‐Doped Selenide Glasses for Potential 1.6 μm Optical Amplifier Materials

1.6 µm emission originated from Pr³⁺: (³F₃, ³F₄) → ³H₄ transition in Pr³⁺‐ and Pr³⁺/Er³⁺‐doped selenide glasses was investigated under an optical pump of a conventional 1480 nm laser diode. The measured peak wavelength and full‐width at half‐maximum of the fluorescent emission are ~1650 nm and ~120 nm, respectively. A moderate lifetime of the thermally coupled upper manifolds of ~212 ± 10 µs together with a high stimulated emission cross‐section of ~(3 ± 1)×10^??20 cm² promises to be useful for 1.6 µm band fiber‐optic amplifiers that can be pumped with an existing high‐power 1480 nm laser diode. Codoping Er³⁺ enhances the emission intensity by way of a nonradiative Er³+: ⁴I_{13/2 →} Pr³⁺: (³F₃, ³F₄) energy transfer. The Dexter model based on the spectral overlap between donor emission and acceptor absorption describes well the energy transfer from Er³⁺ to Pr³⁺ in these glasses. Also discussed in this paper are major transmission loss mechanisms of a selenide glass optical fiber.     

用于WDM系统的S-波段光纤放大器的研究

介绍了用于WDM系统的S－波段光纤放大器的两种实现方案：掺铥光纤放大器和拉曼光纤放大器。并对其原理、特点、性能、研究现状及存在的难点进行了详细的论述和分析。     

掺Er3+钨碲玻璃光纤放大器的特性研究

以WO₃、TeO₂、ZnO和Na₂O为基质制备了掺Er³⁺钨碲(EDWTZn)玻璃.差热分析表明EDWTZn玻璃的转变温度达到427℃,比常规碲酸盐玻璃具有更高的热稳定性.McCumber原理研究的结果显示,EDWTZn玻璃在1530nm处的峰值受激发射截面和荧光发射半高宽分别为9.52×10^-21cm²和86nm.数值模拟结果表明,EDWTZn光纤放大器利用较短的激活长度就可获得足够的信号光放大,在1530nm波长附近能提供极宽的平坦增益带,当输入信号光功率为0dBm时,在大约70nm带宽范围内的平均信号增益大于20dB,不平坦度小于5dB.     

1053 nm掺Yb3+双包层光纤放大器脉冲放大特性研究

从掺Yb^3＋光纤放大器（YDFA）的功率传输方程出发，采用有限差分法对掺Yb^3＋双包层光纤放大器在1053nm的脉冲放大特性进行数值分析。模拟计算了在977nm前向抽运下，光纤放大器中的上能级粒子数，抽运光和放大自发辐射（ASE）在光纤中的稳态分布。分析了掺Yb^3＋双包层光纤放大器的单脉冲波形畸变以及控制输入脉冲形状来产生需要的超高斯输出脉冲形状。讨论了最佳长度以及抽运方式差别等问题。     

双包层铒镱共掺光纤放大器功率漂移及控制

基于速率方程的离散算法,分析了双包层Er3+/Yb3+光纤放大器增益动态的特性。研究了功率漂移与撤除信道数的关系及不同控制方式的控制效果。结果表明:信道撤除数量越多,放大器达到稳态的时间越长,功率漂移越大;泵浦控制方式下,泵浦功率的调整随撤除信道数的增加而增大,且抑制功率漂移的时间也随之增长;反馈控制方式下,功率漂移首先呈现振荡结构,抑制功率漂移的时间较短。     

A Fully‐Integrated Penta‐Band Tx Reconfigurable Power Amplifier with SOI CMOS Switches for Mobile Handset Applications

A fully‐integrated penta‐band reconfigurable power amplifier (PA) is developed for handset Tx applications. The output structure of the proposed PA is composed of the fixed output matching network, power and frequency reconfigurable networks, and post‐PA distribution switches. In this work, a new reconfiguration technique is proposed for a specific band requiring power and frequency reconfiguration simultaneously. The design parameters for the proposed reconfiguration are newly derived and applied to the PA. To reduce the module size, the switches of reconfigurable output networks and post‐PA switches are integrated into a single IC using a 0.18 μm silicon‐on‐insulator CMOS process, and a compact size of 5 mm × 5 mm is thus achieved. The fabricated W‐CDMA PA module shows adjacent channel leakage ratios better than ?39 dBc up to the rated linear power and power‐added efficiencies of higher than around 38% at the maximum linear output power over all the bands. Efficiency degradation is limited to 2.5% to 3% compared to the single‐band reference PA.     

基于1S0能级的Pr3+:ZBLAN光纤上转换紫外激光的数值模拟

在Pr3 ∶ZBLAN光纤中,运用粒子数速率方程理论,研究用586 nm和335 nm连续激光双光子激发4f组态最高能级1S0,以1S0和3F4为激光上下能级实现250 nm上转换紫外激光的动力学行为,得到阈值抽运功率、激光输出功率、斜率效率和最佳光纤长度等激光参数。结果表明,阈值抽运功率随光纤长度增加而增大,斜率效率随光纤长度增加而减小,光纤较短时,无法获得较高输出功率。掺杂浓度越大则阈值抽运功率越小,斜率效率越大。在选取的特定条件下,斜率效率最高可达16.7%。     

采用增益均衡技术的Er^3＋／Vb^3＋双包层光纤放大器

根据长周期光纤光栅（LPG）的透射谱公式，分析了长周期光纤光栅均衡滤波器的特性，并对Er^3＋／Yb^3＋双包层光纤和集束熔锥耦合结构的光纤放大器进行了实验研究。结合不使用增益平坦技术条件下增益特性曲线的特点，设计了一种由三个LPG组成的均衡滤波器。实验结果表明，在1525～1565nm波段上实现了50个信道的WDM光放大输出，平坦度为0．3dB。     

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     

Er^3＋—Yb^3＋双掺杂有源光纤

报道了制造Ｅｒ＾３＋－Ｙｂ＾３＋双掺单模有源光纤的溶液掺杂技术，此光纤经紫外辐照后中收峰处损耗明显增加，而低损耗区损耗几乎不变。对激光器件应用而言，认为几百ｐｐｍ浓度和Ｙｂ＾３＋：Ｅｒ＾３＋＝２０：１掺杂比是合适的。探讨了Ｅｒ＾３＋和Ｙｂ＾３＋能级间相互跃迁机理，通过二者的交叉驰豫提高了泵哺吸收带范围和热稳定性。     

A Ka‐Band 6‐W High Power MMIC Amplifier with High Linearity for VSAT Applications

A Ka‐band 6‐W high power microwave monolithic integrated circuit amplifier for use in a very small aperture terminal system requiring high linearity is designed and fabricated using commercial 0.15‐μm GaAs pHEMT technology. This three‐stage amplifier, with a chip size of 22.1 mm² can achieve a saturated output power of 6 W with a 21% power‐added efficiency and 15‐dB small signal gain over a frequency range of 28.5 GHz to 30.5 GHz. To obtain high linearity, the amplifier employs a class‐A bias and demonstrates an output third‐order intercept point of greater than 43.5 dBm over the above‐mentioned frequency range.     

An All‐Optical Gain‐Controlled Amplifier for Bidirectional Transmission

A novel all‐optical gain‐controlled (AOGC) bidirectional amplifier is proposed and demonstrated in a compact structure. The AOGC function using fiber Bragg grating (FBG) pairs controls both directional signals independently, and combinations of optical interleavers and isolators suppress Rayleigh backscattering (RB) noise. The amplifier achieves high and constant gain with a wide dynamic input signal range and low noise figure. The performance does not depend on the input signal conditions, whether static‐state or transient signals, or whether there is symmetric or asymmetric data traffic on bidirectional transmission. Transmission comparison experiments between invariable symmetrical and random variable asymmetric bidirectional data traffic verify that the all‐optical gain control and bidirectional amplification functions are successfully combined into this proposed amplifier.     

A 60 GHz Medium Power Amplifier for Radio‐over‐Fiber System

We present the design and fabrication of a 60 GHz medium power amplifier monolithic microwave integrated circuit with excellent gain‐flatness for a 60 GHz radio‐over‐fiber system. The circuit has a 4‐stage structure using microstrip coupled lines instead of metal‐insulator‐metal capacitors for unconditional stability of the amplifier and yield enhancement. The gains of each stage of the amplifier are modified to provide broadband characteristics of input/output matching for the first and fourth stages and to achieve higher gains for the second and third stages to improve the gain‐flatness of the amplifier for wideband.     

全光纤化高效Er3+-Yb3+共掺光纤放大器的实验研究

对全光纤化高功率Er<'3+>-Yb<'3+>共掺光纤(EYDF)放大器进行了实验研究.采用小芯径双包层EYDF作为增益介质,多模高功率915 nm半导体激光器作为泵浦源,实现了EYDF放大器的全光纤化.对分布反馈(DFB)激光器输出的窄带信号进行放大,得到了斜率效率约为27.2%、最高2.14 W的高功率输出;实验中...     

新型超宽带光纤放大器的研究进展

探讨了超宽带光纤放大器发展的三个方向,并按实现方式的不同,对几种典型的新型宽带光纤放大器从原理、结构、特性和发展现状等方面进行了综述。     

掺Pr~（3＋）氟化物玻璃光谱和发光特性的研究

制备了几种不同化学成分的掺Ｐｒ３＋氟化物玻璃，测定了玻璃的吸收光谱和荧光光谱。根据Ｊｕｄｄ－Ｏｆｅｌｔ理论模型研究了玻璃成分对Ｐｒ３＋发光性质的影响。结果表明，Ｐｒ３＋在氟锆酸盐玻璃中的发光性能优于氟铝酸盐和氟磷酸盐玻璃中的发光性能，随着ＮａＦ被ＮａＣｌ的取代，发光性能进一步改善。     

激光二极管抽运掺Yb3+光纤放大器获得2.41W超短脉冲输出

对国产掺镱(Yb3 )双包层大模场面积光纤超短脉冲放大器进行了系统的实验研究。以自己搭建的脉冲宽度为2.3ps,重复频率为95MHz的全固态锁模激光器作为种子源,以976nm大功率光纤耦合激光二极管为抽运源,以1.6m国产掺Yb3 双包层大模场面积光纤为增益介质,在11.2W的入纤抽运功率下,将平均功率为100mW的脉冲种子光放大到平均功率2.41W,单脉冲能量达到了25nJ,放大后脉冲的宽度(时域宽度)和光谱都有所展宽。     

A Compact C‐Band 50 W AlGaN/GaN High‐Power MMIC Amplifier for Radar Applications

A C‐band 50 W high‐power microwave monolithic integrated circuit amplifier for use in a phased‐array radar system was designed and fabricated using commercial 0.25 μm AlGaN/GaN technology. This two‐stage amplifier can achieve a saturated output power of 50 W with higher than 35% power‐added efficiency and 22 dB small‐signal gain over a frequency range of 5.5 GHz to 6.2 GHz. With a compact 14.82 mm² chip area, an output power density of 3.2 W/mm² is demonstrated.