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High-Power Raman Soliton Generation at 1.7 μm in All-Fiber Polarization-Maintaining Erbium-Doped amplifier

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Chinese Physics Letters 2024年第5期41卷 35-39页

作者：徐子鹏王萱姚传飞杨林京李平雪 Institute of Ultrashort Pulsed Laser and Application Beijing University of TechnologyBeijing 100124China

An all-fiber polarization maintaining high-power laser system operating at 1.7 μm based on the Ramaninduced soliton self-frequency shifting effect is demonstrated. The entirely fiberized system is built by erbiumdoped oscillator and two-stage amplifiers with polarization maintaining commercial silica fibers and devices, which can provide robust and stable soliton generation. High-power soliton laser with the average power of 0.28 W,the repetition rate of 42.7 MHz, and pulse duration of 515 fs is generated directly from the main *** experiment provides a feasible method for high-power all-fiber polarization maintaining femtosecond laser generation working at 1.7 μm.

关键词： polarization fiber amplifier

Splicing technology of Ti:sapphire crystals for a high-energy chirped pulse amplifier laser system

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High Power Laser Science and Engineering 2014年第2期2卷 1-8页

作者： Yanqi Liu Yuxin Leng Xiaoming Lu Yi Xu Cheng Wang State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

We develop a splicing technology of Ti:sapphire crystals for a high-energy chirped pulse amplifier laser system that can suppress the parasitic lasing to improve the amplification efficiency compared to a large-size single Ti:sapphire crystal amplifier. Theoretical investigations on the characteristics of the amplifier with four splicing Ti:sapphire crystals,such as parasitic-lasing suppression and amplification efficiencies, are carried out. Some possible issues resulting from this splicing technology, including spectral modulation, stretching or splitting of the temporal profile, and the sidelobe generation in the spatial domain(near field and far field), are also investigated. Moreover, the feasibility of the splicing technology is preliminarily demonstrated in an experiment with a small splicing Ti:sapphire crystals amplifier. The temporal profile and spatial distribution of the output pulse from the splicing Ti:sapphire crystal amplifier are discussed in relation to the output pulse from a single Ti:sapphire crystal amplifier.

关键词： chirped pulse amplification splicing technology Ti:sapphire crystal amplifier

New thermal optimization scheme of power module in solid-state amplifier

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Nuclear Science and Techniques 2019年第4期30卷 143-149页

作者： Lie-Peng Sun Zhen-Yu Yuan Cheng Zhang Xian-Bo Xu Jun-Gang Miao Jian-Hua Zhang Long-Bo Shi Yuan He Beijing BBEF Science and Technology Co. Ltd. Institute of Modern Physics Chinese Academy of Sciences Beihang University

The new 1 kW power module for ADS project needs the optimization of cooling design including water flow and tunnel layout, and the water flow of three tons per hour was chosen to be a goal for a 20 kW power *** to analysis from the insertion and integrated loss, about 24 modules were integrated into the rated power. Thus, every module has a cooling flow of 2.1 L/min for RF heat load and power supply loss, which is very hard to achieve if no special consideration and techniques. A new thermal simulation method was introduced for thermal analysis of cooling plate through CST multi-physics suite,especially for temperature of power LDMOS *** specific measures carried out for the higher heat transfer were also presented in this paper.

关键词： RF system Solid-state amplifier Power module Heat transfer coefficient

A 600W Broadband Doherty Power amplifier with Improved Linearity for Wireless Communication System

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China Communications 2017年第2期14卷 21-29页

作者： Jing Li Wenhua Chen Qian Zhang Department of Electronic Engineering Tsinghua University Beijing 100084 China

An asymmetric Doherty architecture based on three identical transistors is proposed in this paper. This proposed *** topology reduces the difficulty in designing matching networks brought by the low optimal impedance of high power transistors. And the inverted Doherty topology as well as carefully chosen value of load impedance makes it possible to extend the bandwidth of high power amplifiers. Besides, bias networks of this proposed *** architecture are also carefully considered to improve the linearity. The proposed high power *** Doherty power amplifier(***) is designed and fabricated based on theoretic analysis. Its maximum output power is about 600 Watts and the drain efficiency is above 35.5% at 9d B back off output power level from 1.9GHz to 2.2 GHz and the saturated drain efficiency is above 47% across the whole frequency band. The measured concurrent *** results suggest that the linearity of DPA is improved by at least 5d B.

关键词： amplifier inverted Doherty linearity high power

Analysis and implementation of derivative superposition for a power amplifier driver

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Journal of Semiconductors 2012年第4期33卷 81-88页

作者：李一雷韩科峰闫娜谈熙闵昊 ASIC&System State Key Laboratory Fudan UniversityShanghai 201203China

A new expression is proposed to analyze the linearization effectiveness of derivative superposition （DS） with large and small signal inputs, and different optimization methods of DS are found for different input magni tudes. A power amplifier driver （PAD） with largesignal optimized DS was implemented in 0.13/,m technology within a reconfigurable RF transmitter. The PAD is compatible with the GSM band at 900 MHz and the WCDMA band at 1.95 GHz, and it has a gain range of 44 dB with a step of 2 dB. Measurement results show that the over all OIP3 of the transmitter is better than 19 dBm, and the output referred 1dB compression point is better than 7.5 dBm.

关键词： amplifier linearity derivative superposition

HIGH-GAIN COHERENT CW IMAGE amplifier WITH A BaTiO_(3) CRYSTAL

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Chinese Physics Letters 1989年第6期6卷 284-285页

作者： ZHANG Zhiguo WANG Dadi JIANG Yandao ZHANG Shiming JIN Fuhui YE Peixian Institute of Physics Academia Sinica Beijing

Recently optical amplifiers with a gain factor of 4000 have been cons true ted using photorefractive BaTiO_(3) crystal and CW At+laser^(1,2).In this letter we report for the first time that a high-gain coherent CW image amplifier was constructed by using two-wave coupling in a BaTiO_(3) crystal,and a gain factor of 21400 has been achieved successfully.

关键词： amplifier gain (3)

Homotopic mapping solving method for gain fluency of a laser pulse amplifier

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Science China(Physics,Mechanics & Astronomy) 2009年第7期52卷 1007-1010页

作者： MO JiaQi1,2 1 Anhui Normal University, Wuhu 241000, China 2 Division of Computational Science, E-Institutes of Shanghai Universities, at SJTU, Shanghai 200240, China Anhui Normal University Wuhu China Division of Computational Science E-Institutes of Shanghai Universities at SJTU Shanghai China

The model for gain fluency of a laser pulse amplifier is studied. Using the homotopic mapping method, firstly, the system of the original model is packed up standardization; secondly, introducing a homotopic mapping, taking the property of the mapping, inducing a contrived parameter, the solving of a nonlinear problem translates into the solving of a linear problem. Then the approximate expressions of the solution for the corresponding model are obtained. And the precision for the approximate solution is compared. It illuminates that the obtained approximate solution using the homotopic mapping method possesses higher approximate degree. At one time, the expansion of solution through the homotopic mapping method can be kept in the analytic operation. Thus it also enables us through differential and integral operations to obtain other physics behavior for the gain fluency of laser pulse amplifier.

关键词： nonlinear homotopic mapping laser pulse amplifier

Experimental studies of high order soliton compression effect and gain characteristics in femtosecond laser pulses E_r^(3+)-doped fiber amplifier

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Science China Mathematics 2000年第3期43卷 299-306页

作者：刘东峰陈国夫白晋涛王贤华 State Key Laboratory of Transient Optics Technology Xi'an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi'an 710068 China

Seed laser pulses with average power of 146 pW and pulse duration of 480 fs were amplified to 14.5 mW. The pulse duration was compressed to 260 fs using 6 m high concentration Er3+ -doped fiber under forward pumping. The amplified signal pulse energy was 0.691 nJ (corresponding to a peak power of 2 657.7 W) and the repetition rate was 20.84 MHz. Spectrum breakup was observed simultaneously. The spectrum of pulses amplified by 3 m Er3+ -doped fiber remains a single peak under different pump power. The amplified pulse duration was compressed abnormally with the increasing pump power using the backward pumping; that is, the amplified pulses were compressed with the increasing pump power under low pump power. When the pump power reached 38 mW, the shortest amplified pulse duration was 309 fs. With further increase in pump power, the amplified pulses began broadening, accompanied by a single peak spectrum under different pump power.

关键词： ultrafast optics transient optics femtosecond optics optical fiber amplifier femtosecond laser amplification laser technology soliton optical fiber communication.

Thulium-Doped Fiber amplifier for Blue Light Signal Amplification

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China Communications 2019年第5期16卷 181-188页

作者： Muhammad Hanif Ahmed Khan Khushik Chun Jiang State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong University

Fluoride-based thulium-doped visible light fiber amplifier(TmVLFA), which can be used to amplify the blue light signal for a visible light communication(VLC) system,is theoretically demonstrated for the first time according to the best of our knowledge. The transition rate equations and power propagation equations are solved to predict the dependence of the gain and noise figure on fiber parameters. The numerical results show that with the pump wavelength 1150 nm and pump power 800 mW, 2.75 m long thulium-doped fiber can amplify blue light(480 nm) signal up to 33.3 dB, and the noise figure is in the range from 3.0 to 3.5 dB. The model and numerical results encourage the use of fiber amplifier in VLC system for blue light amplification to extend the range of VLC.

关键词： Tm-doped visible light fiber amplifier visible light communication fiber amplifier gain noise figure