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An Experiment for Generating the 14-Tone Stable Carriers Using Recirculating Frequency Shifter

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Chinese Physics Letters 2010年第9期27卷 103-106页

作者：田凤张晓光李建平席丽霞 Key Laboratory of Information Photonics and optical Communications (BUPT) (Ministry of Education) Beijing University of Posts and Telecommunications Beijing 100876

In experiment, the generation of 14-tone stable carriers with recirculating frequency shifter is realized. Some factors that impact the performance of the carrier generation are discussed. It is experimentally found that the balance and the insertion loss of the inphase/quadrature （I/Q,） modulator, the accurate π/2 phase difference and equal power level of two rf signals which are applied to the two ports of the I/Q, modulator, the gain of the optical amplifier, the bandwidth and sharp window spectrum of the tunable filter and the stability of the optical signals＇ states of polarization fed into I/Q, modulator, play important roles in the generation of a stable multi-tone carrier source. By employing appropriate techniques we obtain 14-tone stable carriers in the experiment.

关键词： RADIO frequency modulation PHASE shifters NUMERICAL integration STABILITY (Mechanics) POLARIZATION (Electricity) optical amplifiers SPECTRUM analysis

High-Frequency Einstein-Podolsky-Rosen Entanglement via Atomic Memory Effects in Four-Wave Mixing

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Chinese Physics Letters 2010年第9期27卷 111-114页

作者：张雪华胡响明孔令峰张秀 Department of Physics Huazhong Normal University Wuhan 430079

Atomic memory effects occur when the atomic relaxation times are comparable to or much longer than the cavlty relaxation times. We show that by using the memory effects, it is possible to obtain high-frequency Einstein- Podolsky-tlosen entanglement between a pair of Stokes and anti-Stokes fields in a four-wave mixing system. The physical origin is traced to the dynamical Stark splittings of dressed states due to the parametrically amplified fields. This mechanism provides an alternative and efficient way for sideband entanglement.

关键词： SHORTWAVE radio EINSTEIN-Podolsky-Rosen experiment RELAXATION (Nuclear physics) optical amplifiers NUCLEAR energy FIELD theory (Physics)

Analysis of Pulse Tolerance to Pump Depletion Induced Noise in DWDM Systems Using Distributed Fiber Raman amplifiers

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Chinese Journal of Lasers 2002年第3期11卷 60-63页

作者： YAN Minhui CHEN Jianping LI Jianlang JINAG Wenning CHEN Junfeng LI Xin (The State Key Laboratory on Fiber Optic Local Area Communication Networks and Advanced optical Communication Systems, Shanghai Jiao Tong University, Shanghai 200030, China) 上海交通大学 The State Key Laboratory on Fiber-Optic LocalArea Communication Networks and Advanced Optical Communication Systems 上海 200030

In distributed optical fiber Raman amplifiers, instantaneous pump power depletion is related to patterns of input DWDM signals and results in extra optical noise and crosstalk. This noise has different effects on non return to zero (NRZ) and return to zero (RZ) pulse forms. These phenomena are compared with present simulation results.

关键词： Raman scattering optical amplifiers dense wavelength division multiplexing crosstalk optical noise

Digital twin modeling and controlling of optical power evolution enabling autonomous-driving optical networks:a Bayesian approach

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Advanced Photonics 2024年第2期6卷 69-80页

作者： Xiaomin Liu Yihao Zhang Yuli Chen Yichen Liu Meng Cai Qizhi Qiu Mengfan Fu Lilin Yi Weisheng Hu Qunbi Zhuge Shanghai Jiao Tong University State Key Laboratory of Advanced Optical Communication Systems and NetworksDepartment of Electronic EngineeringShanghaiChina

optical networks are evolving toward ultrawide bandwidth and autonomous *** this scenario,it is crucial to accurately model and control optical power evolutions(OPEs)through optical amplifiers(OAs),as they directly affect the signal-to-noise ratio and fiber ***,a fundamental contradiction arises between the complex physical phenomena in optical transmission and the required precision in network *** theoretical methods underperform due to ideal assumptions,while data-driven approaches entail exorbitant costs associated with acquiring massive amounts of data to achieve the desired level of *** this work,we propose a Bayesian inference framework(BIF)to construct the digital twin of OAs and control OPE in a data-efficient *** the informative data are collected to balance the exploration and exploitation of the data space,thus enabling efficient autonomous-driving optical networks(ADONs).Simulations and experiments demonstrate that the BIF can reduce the data size for modeling erbium-doped fiber amplifiers by 80%and Raman amplifiers by 60%.Within 30 iterations,the optimal controlling performance can be achieved to realize target signal/gain profiles in links with different types of *** results show that the BIF paves the way to accurately model and control OPE for future ADONs.

关键词： optical fiber communications digital twin Bayesian inference optical amplifiers autonomous-driving optical networks

Design of an optical slot waveguide amplifier based on Er^(3+)-doped tellurite glass

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Chinese Optics Letters 2023年第1期21卷 91-96页

作者：卫宁李晓博何佳晶范永涛但亚平王俊 Laboratory of Micro-Nano Optoelectronic Materials and Devices Key Laboratory of Materials for High-Power LaserShanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong UniversityShanghai 200240China CAS Center for Excellence in Ultra-intense Laser Science(CEULS) Shanghai 201800China State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China

The idea of a slot waveguide amplifier based on erbium-doped tellurite glass is first theoretically discussed in this *** the horizontal slot for low propagation loss,the TM mode profile compressed in the insertion layer was simulated,and the gain characteristics of the slot waveguide amplifier were *** the capacity to confine light locally and the merits of tellurite glass as an emission host,this optimized amplifier shows enhanced interactions between the electric field and erbium ions and achieves a net gain of 15.21 dB for the 0.01 mW input light at 1530 nm,implying great promise of a high-performance device.

关键词： guided waves optical amplifiers rare-earth-doped materials

Weak laser pulse signal amplification based on a fiber Brillouin amplifier

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Chinese Optics Letters 2018年第11期16卷 66-69页

作者： Liwen Sheng Dexin Ba Zhiwei Lü National Key Laboratory of Science and Technology on Tunable Laser Harbin Institute of TechnologyHarbin 150001China Corresponding author： dexinba@*** corresponding author： lvzw@***

We propose a high-gain and frequency-selective amplifier for a weak optical signal based on stimulated Brillouin scattering in a single mode fiber. To be able to satisfy the needs of high gain and high signal-to-noise ratio laser pulse amplification, different fiber lengths and core diameters are used to fulfill this experiment. In the experiment, a 430 nW （peak power） pulsed signal is amplified by 70 dB with a signal-to-noise ratio of 14 dB. The small size, high gain, low cost, and low noise of the fiber Brillouin amplifier make it a promising weak signal amplification method for practical applications such as lidar.

关键词： Fiber optic amplifiers Lidar optical amplifiers optical signals Single mode fibers Stimulated Brillouin scattering

Single crystal erbium compound nanowires as high gain material for on-chip light source applications

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Frontiers of Optoelectronics 2016年第2期9卷 312-317页

作者： Zhicheng LIU Hao SUN Leijun YIN Yongzhuo LI Jianxing ZHANG Cun-Zheng NING School of Electrical Computer and Energy Engineering Arizona State University Tempe Arizona 85287 USA Department of Electronic Engineering Tsinghua University Beijing 100084 China

Integrated photonics requires high gain optical materials in the telecom wavelength range for optical amplifiers and coherent light sources. Erbium （Er） containing materials are ideal candidates due to the 1.5 μm emission from Era＋ ions. However, the Er density in typical Er-doped materials is less than 10^20 cm-3, thus limiting the maximum optical gain to a few dB/cm, too small to be useful for integrated photonic applications. Er compounds could potentially solve this problem since they contain much higher Era＋ density. So far the existing Er compounds suffer from short lifetime and strong upconversion effects, mainly due to poor crystal qualities. Recently, we explore a new Er compound： erbium chloride silicate （ECS, Er3（SiO4）2C1） in the form of nanowire, which facilitates the growth of high quality single crystal with relatively large Era＋ density 0.62 ×10^22 cm^-3）. Previous optical results show that the high crystal quality of ECS material leads to a long lifetime up to 1 ms. The Er lifetime-density product was found to be the largest among all the Er containing materials. Pump-probe experiments demonstrated a 644 dB/cm signal enhancement and 30 dB/cm net gain per unit length from a single ECS wire. As a result, such high-gain ECS nanowires can be potentially fabricated into ultra-compact lasers. Even though a single ECS nanowire naturally serves as good wavegnide, additional feedback mechanism is needed to form an ultra-compact laser. In this work, we demonstrate the direct fabrication of 1D photonic crystal （PhC） air hole array structure on a single ECS nanowire using focused ion beam （FIB）. Transmission measurement shows polarization-dependent stop-band behavior. For transverse electric （TE） polarization, we observed stop-band suppression as much as 12 dB with a 9 μm long airholed structure. Through numerical simulation, we showed that Ω-factor as high as 11000 can be achieved at 1.53 μm for a 1D PhC micro-cavity on an ECS nanowire. Such a high Q cavity co

关键词： nanomaterials rare-earth-doped materials,lasers optical amplifiers nanostructure fabrication micro-cavity devices

Analysis of the maximum extractable power of photonic crystal fiber lasers

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Chinese Optics Letters 2014年第A02期12卷 92-95页

作者：郭凯王小林罗成周朴舒柏宏 College of Optoelectronics Science and Engineering National University of Defense Technology Changsha 410073 China

In this article, we analyze the factors that limit the output power increase for photonic crystal fiber lasers and set a theoretical model to calculate the maximum extractable power of ytterbium-doped photonic crystal fibers. Numerically, when the diameter of core is 76-μm and the pumping intensity is 0.21 W/（μm^2× Sr）, the output of pure silica and ytterbium-doped photonic crystal fiber lasers is 100-kW, considering the technology for the time being. The main limitations of power scaling are facet damage and thermal self-focusing. In case of the strict single-mode operation condition, the maximum extractable power is 100-kW when the numerical aperture is 0.05. Considering the strict single-frequency operation condition, the maximum extractable power of both pure silica and ytterbium-doped photonic crystal fiber lasers is 1.65-kW, where the main factor is stimulated Brillouin scattering effect. Compared with the previous results, the increase in the maximum extractable power depends on three parameters： the availability of high-brightness pump diodes, the endless single-mode characteristic of the photonic crystal fiber, and the high doping density which lead to efficient absorption coefficient of pumping light. Finally, we simulate numerical aperture that influences the maximum power of photonic crystal fiber lasers and compare the difference in maximum output power of photonic crystal fibers and double-cladding fiber lasers in single-frequency condition.

关键词： 140.3280 Laser amplifiers 140.4480 optical amplifiers 140.3510 Lasers, fiber 140.3500 Lasers, erbium

Research on effects of active fiber length and dopant concentration on 976-nm Yb-doped fiber amplifiers

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Chinese Optics Letters 2013年第14期11卷 26-29页

作者：王睿星曹涧秋刘莹郭少锋陈金宝 College of Opto-Electronic Science and Engineering National University of Defense Technology Changsha 410073 China

In this letter, the theoretical model and rate equations of Ytterbium-doped double-clad fiber amplifiers are introduced. The output performance of fiber amplifiers is analyzed through numerical simulations considering three main factors： active fiber length, pump power, and dopant concentration. It is found that the output signal power experiences a stable growth and then decreases rapidly as the active fiber length becomes longer. It is also revealed that the dopant concentration shows similar effects as active fiber length on the output signal power of fiber amplifiers.

关键词： 060.2320 Fiber optics amplifiers and oscillators 140.3615 Lasers, ytterbium 140.4480 optical amplifiers 060.2280 Fiber design and fabrication