133-W pulsed fiber amplifier with large-mode-area fiber

A master-oscillator fiber power amplifier (MOPA) system with a 4-m-long Yb3+-doped homemade large mode area (LMA) double-clad fiber is reported. The system emits up to 133.8 W of amplified radiation at a wavelength of 1064 nm and a repetition rate of 100 kHz, limited only by the available pump power. Peak power of 300 kW at 20 kHz with a pulse duration of 15 ns is obtained. (c) 2006 Society of Photo-Optical Instrumentation Engineers.

133-W pulsed fiber amplifier with large-mode-area fiber

A master-oscillator fiber power amplifier (MOPA) system with a 4-m-long Yb3+-doped homemade large mode area (LMA) double-clad fiber is reported. The system emits up to 133.8 W of amplified radiation at a wavelength of 1064 nm and a repetition rate of 100 kHz, limited only by the available pump power. Peak power of 300 kW at 20 kHz with a pulse duration of 15 ns is obtained. (c) 2006 Society of Photo-Optical Instrumentation Engineers.

A four-passed ytterbium-doped fiber amplifier

In this paper, a four-passed ytterbium-doped fiber amplifier (YDFA) is discussed. The gain and the pump and the signal light propagation characteristics of the four-passed YDFA are described. It is found that, while using a shorter length of the fiber, a four-passed fiber amplifier can realize the same output power as a single-pass fiber amplifier, and, for the same fiber lengths, a four-passed fiber amplifier offers a significantly higher power than its single-pass counterpart. (C) 2006 Elsevier Ltd. All rights reserved.

Spectrum broadening and reshaping via gain compensation of fiber amplifier

We report a novel technique to broaden and reshape the spectrum of picosecond laser pulse based on the seeder of gain switch laser diode and Yb(3+)-doped fiber amplifier (YDFA). From compensating the seed spectrum with the gain of YDFA, the seed pulse of 7 nm bandwidth is broadened to 20 nm, and the flat top spectral shape is obtained as well. A self-made fiber coupled tunable filter is used to realize the tunable output laser with the wavelength range from 1053 nm to 1073 nm and the line width of 1.4 nm.

高功率双包层光纤放大器

高功率双包层光纤放大器在光纤传感、光纤通讯、光谱测量和惯性约束聚变等领域有广泛应用。介绍了两种获得放大激光输出的高功率双包层光纤放大器：单频双包层光纤放大器和脉冲双包层光纤放大器。分析了它们的工作原理及关键技术，并对国内外近期进展作了综述。

种子光功率对脉冲双包层光纤放大器性能的影响

采用国产的大模场面积双包层光纤和(2+1)×1多模泵浦耦合器，研制出近衍射极限输出的MOPA式脉冲光纤放大器。基于该放大器，发现种子光输出平均功率对放大性能有一定的影响。在泵浦功率一定的情况下，为保证脉冲光纤放大器稳定可靠地运行，对种子光功率来讲，存在一个特定的取值范围。种子光输出平均功率70 mW时，对该脉冲光纤放大器的放大性能进行了研究。

高功率脉冲双包层光纤激光器的新进展

对高功率脉冲双包层光纤激光器的国内外研究进展进行评述，通过建立了小信号瞬态增益模型，对脉冲激光信号经过双包层光纤放大后的波形进行了数值模拟。分析了基于MOPA方式脉冲双包层光纤激光器的几个问题，报道了中科院上海光机所采用振荡-放大（MOPA）方法获得133．8W平均功率脉冲放大输出的实验结果。

Double-cladding Yb3+ fiber for free-space optical communication

The experiment result of Nd:YVO4 laser pumped by laser diode that was amplified by double-cladding Yb3+ fiber is reported. Stable mode-locking pulses are obtained at repetition rate of 320 MHz and the output power is 15 mW. When laser power is amplified by Yb3+- doped double-cladding fiber amplifier, its power can get to 600 mW. Based on these, experiment of double-frequency is carried out, and green laser with power of 4 mW is obtained. (c) 2007 Wiley Periodicals, Inc.

20-W average power, high repetition rate, nanosecond pulse with diffraction limit from an all-fiber MOPA system

In this article, we report an all-fiber master oscillator power amplifier (MOPA) system, which can provide high repetition rate and nanosecond pulse with diffraction-limit. The system was constructed using a (2 + 1) X 1 multimode combiner. The Q-Switched, LD pumped Nd:YVO4 solid-state laser wets used (is master oscillator. The 976-nm fiber-coupled module is used as pump source. A 10-m long China-made Yb3+-doped D-shape double-clad large-mode-area fiber was used as amplifier fiber. The MOPA produced as much as 20-W average power with nanosecond pulse and near diffraction limited. The pulse duration is maintained at about 15 its during 50-175 kHz. The system employs a simple and compact architecture and is therefore suitable for the use in practical applications such as scientific and military airborne LIDAR and imaging. Based oil this system. the amplification performances of. the all fiber amplifier is investigated. (C) 2008 Wiley Periodicals, Inc.

Modeling and optimizing of high-concentration erbium-doped fiber amplifiers with consideration of ion-clusters

Starting from the modeling of isolated ions and ion-clusters, a closed form rate and power evolution equations for high-concentration erbium-doped fiber amplifiers are constructed. Based on the equations, the effects of the fraction of ion-clusters in total ions and the number of ions per cluster on the performance of high-concentration erbium-doped fiber amplifiers are analyzed numerically. The results show that the presence of the ion-clusters deteriorates amplifier performance, such as the signal power, signal gain, the threshold pump power for zero gain, saturated signal gain, and the maximum gain efficiency, etc. The optimum fiber length or other parameters should be modified with the ion-clusters being taken into account for the amplifiers to achieve a better performance. (c) 2007 Elsevier B.V. All rights reserved.