Crostalk in WDM SCM Systems due to SRS

ＣｒｏｓｔａｌｋｉｎＷＤＭＳＣＭＳｙｓｔｅｍｓｄｕｅｔｏＳＲＳＺＨＡＯＬｉａｎｇＸＵＤａｙｏｎｇＷＵＤｅｍｉｎｇＹＵＡＮＨｏｎｇＸＵＡｎｓｈｉ（ＤｅｐａｒｔｍｅｎｔｏｆＥｌｅｃｔｒｏｎｉｃｓ，ＢｅｉｊｉｎｇＵｎｉｖｅｒｓｉｔｙＮａｔｉｏｎａｌＫｅｙＬ...     

Detection Theory of Polydispersities by Dynamic Light Scattering

ＤｅｔｅｃｔｉｏｎＴｈｅｏｒｙｏｆＰｏｌｙｄｉｓｐｅｒｓｉｔｉｅｓｂｙＤｙｎａｍｉｃＬｉｇｈｔＳｃａｔｅｒｉｎｇＺＨＡＮＧＹｉｘｉｎＺＨＵＴｏｕＺＨＡＮＧＪｉａｎｈｕａ（ＤｅｐａｒｔｍｅｎｔｏｆＭｅｃｈａｎｉｃｓ，ＷｕｘｉＵｎｉｖｅｒｓｉｔｙｏｆＬｉ...     

A Comparison of SRS effects between Uni-and Bi-directional WDM Transmission Systems

ＡＣｏｍｐａｒｉｓｏｎｏｆＳＲＳｅｆｅｃｔｓｂｅｔｗｅｅｎＵｎｉ┐ａｎｄＢｉ┐ｄｉｒｅｃｔｉｏｎａｌＷＤＭＴｒａｎｓｍｉｓｉｏｎＳｙｓｔｅｍｓＺＨＡＮＧＫａｎＸＩＥＬｉｎｚｈｅｎＸＵＡｎｓｈｉＷＵＤｅｍｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＥｌｅｃｔｒｏｎ...     

Optical Add/Drop Multiplexers Based on Fiber Gratings Tuned by Magnetic Fields

ＯｐｔｉｃａｌＡｄｄ／ＤｒｏｐＭｕｌｔｉｐｌｅｘｅｒｓＢａｓｅｄｏｎＦｉｂｅｒＧｒａｔｉｎｇｓＴｕｎｅｄｂｙＭａｇｎｅｔｉｃＦｉｅｌｄｓＣＨＥＮＺｈａｎｇｙｕａｎＡＮＨｏｎｇｌｉｎ１）ＺＨＡＮＧＢａｉｃｈｅｎｇＺＨＵＬｉｘｉｎＸＵＡｎｓｈｉＷＵＤｅ...     

Automatic Analysis of the Phase Object Using Projection Moire Deflectometry

ＡｕｔｏｍａｔｉｃＡｎａｌｙｓｉｓｏｆｔｈｅＰｈａｓｅＯｂｊｅｃｔＵｓｉｎｇＰｒｏｊｅｃｔｉｏｎＭｏｉｒｅＤｅｆｌｅｃｔｏｍｅｔｒｙ￥ＷＡＮＧＭｉｎｇ（ＢａｓｉｃＤｅｐａｒｔｍｅｎｔ，ＮａｎｃｈａｎｇＵｎｉｖｅｒｓｉｔｙ，Ｎａｎｃｈａｎｇ３３００２９...     

A Molecular Dynamical Theory of Ultraweak Bio－photon Emission in Living Systems and Its Properties（Ⅱ）

ＡＭｏｌｅｃｕｌａｒＤｙｎａｍｉｃａｌＴｈｅｏｒｙｏｆＵｌｔｒａｗｅａｋＢｉｏ－ｐｈｏｔｏｎＥｍｉｓｓｉｏｎｉｎＬｉｖｉｎｇＳｙｓｔｅｍｓａｎｄｉｔｓＰｒｏｐｅｒｔｉｅｓ（Ⅱ）ＡＭｏｌｅｃｕｌａｒＤｙｎａｍｉｃａｌＴｈｅｏｒｙｏｆＵｌｔｒａｗｅａｋＢ...     

Studies of imaging experiment for photon scanning tunneling microscopy

ＳｔｕｄｉｅｓｏｆｉｍａｇｉｎｇｅｘｐｅｒｉｍｅｎｔｆｏｒｐｈｏｔｏｎｓｃａｎｎｉｎｇｔｕｎｎｅｌｉｎｇｍｉｃｒｏｓｃｏｐｙＧＵＯＮｉｎｇ；ＷＵＳｈｉｆａ；ＸＩＡＤｅｋｕａｎ；ＣＨＵＳｈｉｃａｏ（ＤａｌｉａｎＵｎｉｖｅｒｓｉｔｙｏｆＴｅｃｈｎｏｌｏｇ...     

A Quenched Dye Laser Pumped by a KrF Excimer Laser

ＡＱｕｅｎｃｈｅｄＤｙｅＬａｓｅｒＰｕｍｐｅｄｂｙａＫｒＦＥｘｃｉｍｅｒＬａｓｅｒ￥ＸＵＥＳｈａｏｌｉｎ；ＬＯＵＱｉｈｏｎｇ；ＨＵＡＮＧＨｕｉｊｉｅ；ＤＵＬｏｎｇｌｏｎｇ（ＳｈａｎｇｈａｉＩｎｓｔｉｔｕｔｅｏｆＯｐｔｉｃｓａｎｄＦｉｎｅＭｅｃｈａｎｉ...     

Application of a Double－Wollaston－prism Laser Differential Interferometer in Plasma Focus

ＡｐｐｌｉｃａｔｉｏｎｏｆａＤｏｕｂｌｅ－Ｗｏｌｌａｓｔｏｎ－ｐｒｉｓｍＬａｓｅｒＤｉｆｆｅｒｅｎｔｉａｌＩｎｔｅｒｆｅｒｏｍｅｔｅｒｉｎＰｌａｓｍａＦｏｃｕｓＬＵＭｉｎｇｆａｎｇ；ＹＡＮＧＴｓｉｎｃｈｉ；ＨＡＮＭｉｎ（ＴｓｉｎｇｈｕａＵｎｉｖｅｒｓ...     

The Dynamic Behaviour Analysis of Up－Conversion Luminescence in ErP_5O_（14） Glass

ＴｈｅＤｙｎａｍｉｃＢｅｈａｖｉｏｕｒＡｎａｌｙｓｉｓｏｆＵｐ－ＣｏｎｖｅｒｓｉｏｎＬｕｍｉｎｅｓｃｅｎｃｅｉｎＥｒＰ_５Ｏ_（１４）ＧｌａｓｓＴｈｅＤｙｎａｍｉｃＢｅｈａｖｉｏｕｒＡｎａｌｙｓｉｓｏｆＵｐ－ＣｏｎｖｅｒｓｉｏｎＬｕｍｉｎｅｓｃｅｎｃｅ...     

Theoretical Analysis of the Critical Phenomena of a Brillouin Laser

The critical phenomena of a Brillouin laser are analyzed theoretically. The results show that the behavior of a Brillouin laser in the threshold region is a second-order phase transition. The critical point of the phase transition is the gain threshold of the Brillouin laser, and the order parameter is the amplitude of the Stokes component in stimulated Brillouin scattering. The critical slow-down phenomenon and the typical characteristics in phase transition are demonstrated. Further work on the combination of nonlinear optics and phase transition in the Brillouin laser may lead to a new view and findings that could be significant for both fields.     

Multi-wavelength Brillouin fiber laser using dual-cavity configuration

A simple technique for achieving multi-wavelength tunable multi-wavelength Brillouin fiber laser (BFL) based on dual-pass configuration is demonstrated. The BFL uses a piece of 10 km long non-zero dispersion shifted fiber (NZ-DSF) as a Brillouin gain medium to obtain odd-order Brillouin Stokes waves as an output with the line spacing of 0.16 nm (20 GHz) between each two consecutive waves by employing even-order Brillouin Stokes to improve output performance of the laser. With a BP of 15.3 dBm, at least 15 odd-order Brillouin Stokes and anti-Stokes lines are generated. The laser is room temperature stable, tunable over 50 nm wavelength range and has an optical signal to noise ratio of more than 30 dB at 1560 nm region. This Brillouin fiber laser can operate at any wavelength depending on the Brillouin pump (BP) wavelength used.     

基于激光布里渊散射的高速气流测试技术

激光布里渊散射是由介质密度涨落引起的一种非弹性散射现象,其散射谱特征参数（频移、线宽）取决于散射角和散射介质压强、温度等参数,通过探测高速气流激光布里渊散射谱,可反演获得高速气流压强、温度等参数。介绍了基于激光布里渊散射原理的高速气流参数测试原理,设计了一种基于法布里 珀罗干涉仪的高速气流参数测试装置,搭建实验平台获取了高速氮气气流的激光布里渊散射谱。实验结果表明,通过激光布里渊散射谱获得的高速气流压强、温度值与理论值相对误差在15%以内。     

Operation of brillouin fiber laser in the O-band region as compared to that in the C-band region

A first time O band Brillouin fiber laser is demonstrated and compared with the C band Brillouin fiber laser. By utilizing a 20 km True wave fiber (TWF), the experiment demonstrated four Brillouin lines generated from the simple set-up of Brillouin fiber laser. We compared the threshold between the Brillouin pump wavelength at 1310 nm which represent O band region and 1550 nm for C band region. It shows that the Brillouin threshold at O band region is smaller that C band. The channels spacing between these two bands are also different, where O band have 12.72 GHz spacing while 1550 nm have 10.25 GHz spacing.     

Effect of output coupling ratio on the performance of ring-cavity Brillouin fiber laser

We present a single-wavelength Brillouin fiber laser utilizing a ring-cavity configuration. Performances and characteristics of the laser system have been investigated at different output coupling ratios. The optimum output power of the system stood at 7.3 mW, which was obtained at 90% output coupling ratio. A low Brillouin threshold power of 0.9 mW was obtained at 10% output coupling ratio when the Brillouin pump was set at its maximum power of 24 mW.     

Brillouin-Raman comb fiber laser with cooperative Rayleigh scattering in a linear cavity

We demonstrate a multiple-wavelength Brillouin comb laser with cooperative Rayleigh scattering that uses Raman amplification in dispersion-compensating fiber. The laser resonator is a linear cavity formed by reflector at each end of the dispersion-compensating fiber to improve the reflectivity of the Brillouin Stokes comb. Multiple Brillouin Stokes generation has been improved in terms of optical signal-to-noise ratio and power-level fluctuation between neighboring channels. Furthermore, the linewidth of the Brillouin Stokes is uniform within the laser output bandwidth.     

光纤移频分布式布里渊光纤传感技术

提出了一种利用布里渊光纤环形腔移频技术实现分布式光纤布里渊传感的方法.该方法基于布里渊光时域分析法原理,将一束单纵模运转激光器输出的激光分为两束|一束光入射布里渊光纤环形腔中产生窄线宽的受激布里渊散射光作为斯托克斯光,另一束光经过低频相位调制后作为泵浦光|斯托克斯光和泵浦光分别相向入射进入传感光纤,通过测量布里渊谱得到光纤温度或应变.利用该方法可将十几GHz的微波频率转化为兆赫信号频率进行探测处理,仅需一台激光器,因此系统结构简单、成本低,还可减小激光器频率波动对测量准确度的影响.实验验证了该方法的可行性.     

1064nm红外激光大气布里渊频移量模型

1064nm激光常用于大气环境监测。以激光信号在传输介质中布里渊散射频移量模型为基础,依据相关大气数据建立1064nm激光大气中布里渊散射信号检测的大气探测模型。该模型将布里渊频移量归一为只与大气高度这一单参数相关的函数,详细地描述了0～1000km范围内大气布里渊频移量的连续分布状态。结果表明在0～1000km的海拔高度范围内,1064nm激光大气的布里渊散射频移量以非单调的形式分布在0.5～1.2GHz之间。     

基于宽带光源和自外差检测的布里渊光时域反射温度传感系统

为简化系统结构、减小相干瑞利噪声对系统性能的影响,提出了一种采用宽带光源的瑞利和布里渊散射自外差检测布里渊光时域反射温度传感系统.分析了瑞利和布里渊自外差检测原理,研究了布里渊频移和自外差信号功率与光纤温度和应变的关系.设计并搭建采用宽带光源的自外差检测布里渊光时域反射温度传感系统,获得了常温下沿光纤分布的自外差信号功率谱及不同温度时加温段光纤的功率谱,验证了布里渊频移和自外差信号相对功率变化随温度的线性增加关系.通过实验数据获得的布里渊频移和相对功率变化的温度系数分别为1.07±0.01MHz/℃和(0.37±0.09)%/℃.本文的研究结果为基于瑞利和布里渊自外差检测布里渊光时域反射传感系统的温度和应变同时测量提供了理论和实验依据.     

L-Band Multi-Wavelength Brillouin–Raman Fiber Laser with 20-GHz Channel Spacing

Abstract

A tunable multi-wavelength L-band Brillouin–Raman fiber laser with a 20-GHz channel spacing utilizing bidirectional ring cavity is proposed and experimentally investigated. The laser employs a co-pumped dispersion compensating fiber as a gain medium for both Brillouin and Raman gains. With a Raman pump of 425 mW, the laser system can generate up to 12 double-spaced Brillouin Stokes signals. This simple laser configuration provides stable Brillouin Stokes signals in the absence of self-lasing cavity modes with a tuning range exceeding 35 nm without using any filtering mechanism. The Stokes signals have more than 20 dB of optical signal-to-noise ratio.