Ultrawide 75-nm 3-dB gain-band optical amplification witherbium-doped fluoride fiber amplifiers and distributed Raman amplifiers

An extremely large 3-dB gain-bandwidth of 75 nm (1531-1606 nm) is achieved with a partially gain-flattened erbium-doped fluoride fiber amplifier and a distributed Raman amplifier. The Raman amplifier consists of a 85-km dispersion-shifted fiber (transmission fiber) and a practical 1505-nm Fabry-Perot laser diode pump. 9×2.5 Gb/s wavelength-division-multiplexing (WDM) transmission is successfully demonstrated using two 75-nm gain-band amplifiers as in-line and preamplifiers     

Gain-flattened tellurite-based EDFA with a flat amplificationbandwidth of 76 nm

We describe a tellurite-based Er³⁺-doped fiber amplifier (EDFA) with a flat amplification bandwidth of 76 nm and a noise figure of less than 7 dB. Furthermore, a parallel-type amplifier composed of this EDFA and a 1.45-μm-band Tm³⁺-doped fluoride fiber amplifier achieved a flat amplification bandwidth of 113 nm     

Laser diode pumped operation of Er3+-doped fibreamplifier

Semiconductor laser-diode pumped operation of an erbium-doped fibre amplifier, exhibiting 6 dB gain and operating at 1536 nm, is reported. The amplifier was optically pumped at 807 nm using a self-injection-locked semiconductor laser diode array     

Ultra-wide-band hybrid amplifier consisting of twodispersion-compensating fibres for Raman amplification and thulium-dopedfibre

A novel hybrid amplifier with the largest reported seamless gain-bandwidth of 76 nm (1462-1538 nm) and a peak gain of 31.5 dB is described. The amplifier has a low noise figure, high output power, and a dispersion-compensation function at a signal rate of 10 Gbit/s with an 80 km single mode fibre, over the entire gain bandwidth     

Group delay dispersion measurements in InGaAsP 1.3-μm opticalamplifiers

Group delay dispersion (GDD) of ~15 ps/nm has been measured in a near-traveling-wave optical amplifier at a wavelength where measured gain ripple was ~2 dB, using the envelope phase-shift technique. This is compared to a measured GDD of ~180 ps/nm in a single-facet antireflection-coated amplifier biased below threshold with a gain ripple of ~17 dB. It is shown that these results agree qualitatively with standard theory. An important result is that GDD increases with the square of amplifier length. GDD can be reduced by an order of magnitude if gain ripple is reduced to 0.5 dB     

All-optical limiter using gain flattened fibre parametric amplifier

An all-optical limiting amplifier that is capable of reducing amplitude fluctuations in 20 Gbit/s data packets is presented. The limiting amplifier is based on a gain flattened two-stage fibre parametric amplifier having a record bandwidth of 15 nm     

20 dB gain thulium-doped fluorozirconate fibre amplifier operating at around 0.8 mu m

A thulium-doped fluorozirconate fibre amplifier pumped at 785 nm is described. Amplification is observed from 800 nm to 830 nm, with a small signal gain in excess of 20 dB at 806 nm.<>     

巨磁阻生物传感器阵列及专用锁相放大器设计

EW_GⅠ是基于GMR(巨磁阻)传感器,用于检测血样中特种病毒的正在研发的生物芯片系统。叙述了其巨磁阻传感器阵列以及后端锁相放大IC电路的设计及实现。该阵列包含32个GMR传感器单元和2个传感器参考单元,形成多路的半桥式惠斯通电桥,用于感应绑定磁球的附加磁场。每个单元(100μm×100μm)由长1mm、宽7μm的巨磁电阻蜿蜒而成,该电阻采用[Ag(2nm)/NiFe(6nm)/Cu(2.2nm)/CoFe(4nm)]20结构,采用Ag作为镜面层,其饱和磁场小于等于30mT,GMR值约6%,单个传感器电阻约为780Ω。配套的锁相放大芯片包括了信号通道、参考通道、前置低噪声放大器、带通滤波器、可控增益放大器、相敏检测电路、正交移相电路、差分直流放大电路八个部分,整个设计功耗小于50mW@Vcc=3V。     

利用非线性偏振旋转锁模技术产生0.7nJ,1.5ps光脉冲

为了研究锁模光纤激光器以增益平坦型掺铒光纤放大器作为增益介质对输出特性的影响,采用增益平坦型掺铒光纤放大器结合光纤偏振控制器、偏振相关光隔离器组成锁模光纤激光器,基于非线性偏振旋转锁模技术,实现稳定、自起振锁模运转,得到了中心波长1560nm、重复频率6.495MHz、单脉冲能量0.7nJ、脉宽1.5ps的超短光脉冲。同时实验观察到峰值波长为1557nm和1570nm的双峰值波长锁模脉冲的产生。结果表明,采用增益平坦型掺铒光纤放大器替代普通掺铒光纤组成锁模光纤激光器,可获得较高单脉冲能量的超短光脉冲,锁模脉冲的输出光谱可能出现双峰结构,从而可为超短脉冲光纤激光器设计及实用化提供参考。     

High-gain hybrid amplifier consisting of cascaded fluoride-based TDFA and silica-based EDFA in 1458-1540 nm wavelength region

A hybrid optical fibre amplifier is described that consists of a fluoride-based thulium-doped fibre amplifier and a silica-based erbium-doped fibre amplifier connected in a cascade. The amplifier has a gain of more than 25 dB and a noise figure of less than 9 dB over a wide wavelength region of 1458-1540 nm.     

Wide-band and gain-flattened hybrid fiber amplifier consisting ofan EDFA and a multiwavelength pumped Raman amplifier

A wide-band and finely gain-flattened hybrid fiber amplifier is realized. The seamless 3.0-, 1.3-, and 1.0-dB bandwidths of 80, 76, and 69 nm with relative gain-flatness of 11.3%, 4.7%, and 3.7%, respectively, are achieved for the first time using the amplifier. The amplifier consists of an erbium-doped fiber amplifier, which has a short fluoride-based erbium-doped fiber, a discrete Raman amplifier, which has two isolated Raman fibers pumped simultaneously at three wavelengths, and a small-peak-loss gain-equalizer. The amplifier also yields optical noise figures under 6.0 dB     

UV generation by frequency quadrupling of a Yb-doped fiberamplifier

The pulsed output of a Yb-doped fiber amplifier was frequency doubled and quadrupled to generate visible and UV radiation. When pumped with 150-200 mW at 980 nm and seeded at 1064 nm, the amplifier produced an average power of 90 mW at 1064 nm, 45 mW at 532 nm, and 1.4 mW at 266 nm. These results indicate that frequency-converted fiber lasers and amplifiers will be able to replace conventional tunable UV sources (e,g,, frequency-converted dye lasers) in a number of applications     

REAP: recycled erbium amplifier pump

We report a novel erbium doped fiber preamplifier design with a combination of high gain (>40 dB) and low noise figure (3 dB) at 1556 nm for 80 mW of 980 nm pump power. The co-directional single pumped amplifier employs a composite two stage arrangement in which the second stage is pumped with recycled pump not used in the first stage. In addition, we contrast the amplifier performance trade-offs with the insertions of an isolator or a band pass filter or both in between the two amplifier sections. Finally, we demonstrate a receiver sensitivity of -37 dBm (156 photons/bit) with a 10 Gb/s optical preamplifier regenerator     

Compact 1-W Yb-doped double-cladding fiber amplifier using V-grooveside-pumping

A compact packaged fiber amplifier was constructed using a Yb-doped double-cladding fiber, which was V-groove side-pumped by a laser diode operating at 975 nm. Under saturation, the amplifier generated 1 W at 1064 nm. The small-signal gain reached a maximum of 50 dB at 1075 nm and was greater than 40 dB in the range of 1042-1093 nm     

120-nm bandwidth erbium-doped fiber amplifier in parallel configuration

A new S- to L-band erbium-doped fiber amplifier (EDFA) module, which reaches 120-nm gain bandwidth of 1480 to 1600 nm, has been experimentally investigated and demonstrated by using coupled structure. A 32.8-, 34.7-, and 38.1-dB peak gain is obtained at 1504, 1532, and 1568 nm, respectively, when the input signal power is -30 dBm. In addition, this proposed amplifier also provides a broad-band amplified spontaneous emission (ASE) light source of 1480-1606 nm with the output level above -40 dBm.     

Recent progress in optical amplifiers

State of the art optical amplifier technologies are reviewed focusing on research at ntt. The following developments will be described : an erbium-doped silica fiber with a very high gain coefficient of 11.0 dB/mW, a very small (volume : 36 cc) fiber amplifier module pumped by a 980 nm InGaAs laser diode, an Er-doped fiber amplifier pumped by an AlGalnP visible laser diode, praseodymium-doped fluoride glass fiber amplifiers operating in 1300 nm band, silica-based erbiumdoped planar lightwave circuit amplifiers, and their applications in various optical transmission and measurement systems. The future trends in the optical amplifier research are also described.     

高重频风冷声光调Q光纤激光器实验研究

为了实现功率稳定的风冷高重频脉冲光纤激光器,采用主振荡功率放大结构,对声光调Q的全光纤激光器进行了研究.振荡级采用声光调Q方案,以光纤光栅对为激光器腔镜,915nm激光二极管连续抽运,得到了中心波长1064nm、重复频率10kHz到130kHz可调的激光脉冲输出.采用两级大模场双包层光纤放大,实现了平均功率101W、脉冲宽度328.1ns、3dB光谱宽度0.6nm的激光输出.第二放大级光光转换效率69%,激光器总光光转换效率达62.7%.分析了声光调Q产生的宽种子光脉冲经放大后发生波形畸变的原因.结果表明,采用915nm抽运波长提高了激光器输出激光功率稳定性,在风冷的情况下输出功率长期稳定性优于2%.     

Ultra-wideband tellurite-based Raman fibre amplifier

The first wideband tellurite-based Raman fibre amplifier is described. The amplifier provided a 160 mn bandwidth with a gain of over 10 dB and a noise figure below 10 dB from 1490 to 1650 nm with a tellurite-based fibre only 250 m in length pumped by 4 wavelength channel LDs     

Record-efficient, resonantly-pumped, Er-doped singlemode fibre amplifier

An 85% optical-to-optical efficient, single-frequency performance of resonantly-pumped (at 1476 nm) Yb-free, Er-doped, singlemode fibre amplifier at 1560 nm is reported. The diffraction-limited, single-frequency amplifier is believed to have the highest optical-to-optical efficiency ever reported for Er-doped fibre amplifiers.     

双向多波长泵浦喇曼光纤放大器的优化算法

在变步长的龙格库塔法的基础上,提出利用打靶法,通过先猜测再修正的逐渐逼近的方法来确定计算初始值,进而求解双向泵浦喇曼放大器的功率耦合方程。并利用此算法对三泵浦波长的喇曼放大器进行优化设计,选择泵浦波长分别为1427nm、1445nm和1466nm时进行数值模拟,得到了1dB带宽35nm左右的较好的增益平坦度。