基于薄膜滤光片的新型可重构光分插复用器

研制了一种基于窄带薄膜滤光片的可重构的光分插复用器(ROADM).它由三个单芯光纤准直器、一对三端口光环形器、一对全反射镜和一片特别设计的角度调谐窄带多腔薄膜滤光片组成.通过步进电机的推动调制角度调谐滤光片的倾斜入射角度,从而实现了可选择波长上下路.对该可重构的光分插复用器进行了实验研究,并对该器件的串扰特性进行了详细的分析与计算.实验中得到的上下路信道隔离度大于34 dB,可调谐范围大于26nm,与理论计算结构相符.该种新型的ROADM具有结构简单、可调谐范围大、隔离度高、低偏振相关损耗、成本低等特点,可广泛应用于各种密集波分复用(DWDM)光网络.     

采用原子滤光器的新型激光信标方案研究

提出了采用法拉第反常色散滤光器（ＦＡＤＯＦ）的光电双反馈激光信标新方案。该方案通过数字控制系统和光反馈系统的共同作用，使激光信标系统的稳定性、抗干扰性和可靠性大大提高，并实现了上电自动工作。这种新型激光信标的频率稳定度优于５×１０－９，在３０ｍｓ内可将半导体激光频率稳定在法拉第反常色散滤光器任一透射峰上。该方案可与采用法拉第反常色散滤光器的新型跟瞄系统匹配使用，对建立卫星激光通信链路有重要意义。     

A Novel Fluorescent Biosensor for Detection of Silver Ions Based on Upconversion Nanoparticles

In this paper, we report a simple and sensitive fluorescent biosensor for the quantitative analysis of silver ions (Ag⁺) by using NaYF₄:Yb³⁺, Tm³⁺ upconversion nanoparticles (UCNPs). Ag⁺ could oxidize o-phenylenediamine (OPD) to the oxidized OPD (oxOPD) directly. The fluorescence of UCNPs can be significantly quenched by oxOPD through inner filter effects (IFE). Under the optimized conditions, the Ag⁺ concentration is proportional to the changes of the fluorescence intensity of UCNPs. The proposed method shows high selectivity and Ag⁺ could be quantitatively detected in the range of 0 to 0.5 mM with a low detection limit of 33 nM for Ag⁺. The selectivity and sensitivity of the detection can also be satisfactory. More importantly, this method has potential in practical application to detect Ag⁺ in real samples without interference.     

分子信标的原理、应用及其研究进展

分子信标是一种设计巧妙的新型荧光标记核酸探针。特殊的发夹结构使分子信标具有很强的特异性识别靶标序列的能力 ,目前已成为分子生物学和生物技术中一种强有力的研究工具。本文介绍了分子信标的原理及其在 PCR、核酸序列的分析、活细胞内核酸的动态检测、蛋白质 (酶 )与核酸的相互作用等方面的应用和研究进展。     

一种新型的振荡场光化学传感器

利用法布里珀罗振荡模构造了一种新型的光化学传感器。与传统的以表面等离子模和光导模为探针的迅衰场传感器不同 ,这种新型结构中被传感介质处于法布里珀罗腔的振荡场中 ,其能量在全部入射光能中的比重占得很大 ,使得这种传感器具有很高的灵敏度。实验证实这类传感器对葡萄糖溶液浓度和折射率的测量精度皆可达 10 - 5数量级以上     

A Reconfigurable Microwave Photonic Channelized Receiver Based on Dense Wavelength Division Multiplexing Using an Optical Comb

A photonic approach to implementing a microwave channelized receiver based on dense wavelength division multiplexing using an optical comb is proposed. In the approach, a flat optical comb with 11 comb lines is generated using two cascaded Mach-Zehnder modulators. Frequency analysis of a microwave signal with multiple-frequency components is realized by using the optical comb together with an optical etalon with a periodic transfer function, a wavelength division multiplexer (WDM) and a photodetector array. The system is investigated numerically. Frequency measurement of a multi-frequency signal with a measurement range from 0.5-11.5 with an accuracy of ± 0.5 GHz is achieved. The reconfigurability of the system realized by tuning the comb-line spacing and the peak positions of the etalon is also evaluated. The improvement of the dynamic range of the system using an optimized periodic filter is also discussed.     

一种改进的双边带调制产生光毫米波的方案

提出了应用于光纤无线通信系统中一种改进的双边带调制产生光毫米波方案。在中心站采用强度调制将射频信号调制到光载波上产生一个双边带信号,滤掉中心载波后,利用光交叉复用器把双边带信号的上下边带模分开,将数据速率为2.5Gbit/s的基带信号调制到下边带模后,再与未调信号耦合后产生光毫米波,然后通过单模光纤传输至基站,在基站经过光电转换后产生电毫米波信号。从理论上对该毫米波的色散特性进行了分析,发现毫米波的接收功率不会周期的衰减。同时通过实验研究表明,下行链路信号通过光纤能传输50km而不需要色散补偿,功率代价小于1dBm。因此,该方法产生的光毫米波能有效克服光纤色散引起的信号时延而导致的基带信号退化,适合于远距离传输。     

Highly Sensitive Optical Biosensor for Thrombin Based on Structure Switching Aptamer-Luminescent Silica Nanoparticles

We describe here the construction of a sensitive and selective optical sensor system for the detection of human α-thrombin. The surface functionalized luminescent [Ru(dpsphen)₃]^4? (dpsphen-4,7-diphenyl-1,10-phenanthroline disulfonate) ion doped silica nanoparticles (SiNPs) with a size ~70 nm have been prepared. The DABCYL (2-(4-dimethylaminophenyl)diazenyl-benzoic acid) quencher labeled thrombin binding aptamer is conjugated to the surface of SiNPs using BS³ (bis(sulfosuccinimidyl) suberate) as a cross-linker, resulting in the conformational change of aptamer to form G-quadruplex structure upon the addition of thrombin. The binding event is translated into a change in the luminescence intensity of Ru(II) complex via FRET mechanism, due to the close proximity of DABCYL quencher with SiNPs. The selective detection of thrombin using the SiNPs-aptamer system up to 4 nM is confirmed by comparing its sensitivity towards other proteins. This work demonstrates the application of simple aptamer-SiNPs conjugate as a highly sensitive system for the detection of thrombin and also it is highly sensitive towards thrombin in the presence of other proteins and complex medium such as BSA.     

金属纳米颗粒LSPR光纤生物传感DDA方法研究

研究了金属纳米颗粒的局部表面等离子体共振(LSPR)行为,并讨论了其在光纤生物传感领域的应用.采用离散偶极近似(DDA)的方法,从理论上分析了金属纳米颗粒的尺寸、形状对其传感灵敏度的影响.计算结果显示,金属纳米颗粒的等离子共振吸收峰同时受到颗粒尺寸和形状的影响,但形状对其传感灵敏度的影响最为明显,计算结果与实验数据能较好地吻合.     

基于线阵CCD的光学转速传感器的研究

为克服传统的转速测量方法在瞬时转速测量方面存在的不足，研究了旋转体转速在空间坐标系中的关系，利用线阵CCD技术设计了一种新型光学转速传感器，建立起一种简单的速度压缩模型，解决了旋转机械瞬态性能分析中瞬态转速测量存在的缺陷。     

A Novel Acoustic Emission Fiber Optic Sensor Based on a Single Mode Optical Fiber Coupler

This paper reports, for the first time, on the use of a fused-taper single mode optical fiber coupler as a sensing element for the detection of acoustic emission (AE) and ultrasound. When an acoustic wave impinges on the mode-coupling region of a coupler, the coupling coefficient is modulated via the photo-elastic effect. Therefore, the transfer function of the coupler is modulated by an acoustic wave. The sensitivity of the sensor at 140 kHz was approximately 5.2 mV/Pa and the noise floor was 1 Pa. The bandwidth of the sensor was up to several hundred kHz. This AE sensor exhibits significant advantage compared with interferometer-based AE sensors.     

A Novel Acoustic Emission Fiber Optic Sensor Based on a Single Mode Optical Fiber Coupler

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Optical Nonlinearity in a Novel Optical Signal Regeneration System Based on Cross-Gain Modulation Using Cascaded Semiconductor Optical Amplifiers

We propose a novel optical signal regeneration system based on wavelength converters by use of cross gain modulationin cascaded semiconductor optical amplifiers. The nonlinearity in optical input/output characteristics and eye opening using NRZ signal were archived.     

光放大外腔式光纤法布里-珀罗干涉传感系统

提出了一种大幅度提高外腔式法布里珀罗干涉传感器干涉信号强度的方法 ,利用掺铒光纤放大自发辐射产生的光源代替一般宽带光源 ,同时由于掺铒光纤的放大作用可以放大干涉信号 ,将光纤法布里珀罗传感器的信号强度提高了 4个数量级 ,因而利用该方法可获得很强的信号和较高的信噪比。介绍了基于光放大的外腔式法布里珀罗干涉传感系统的结构、测量原理及实验。实验结果表明该传感器的应变精度为± 10 με,可满足实际应用的要求。该传感系统在大幅度提高传感器信号强度的同时并未提高系统的成本 ,因此有着较高的性价比和实用价值。     

一种基于阶梯状非线性光纤的新颖脉冲压缩方法

提出了一种基于阶梯状非线性光纤的脉冲压缩方法.阶梯状非线性光纤包括普通单模光纤,色散位移光纤和高非线性光纤.数值模拟中所使用的所有元件均在现实中存在,并且与其他脉冲压缩方法相比,此方法成本低且易于控制.数值模拟表明:12.5 ps脉宽,300 mW峰值功率的双曲正割脉冲可被压缩至1.28 ps脉宽,1.3 W峰值功率的脉冲.     

一种新型微机电系统可调光衰减器

一种新型的低成本、小体积的电磁驱动微机电系统可调光衰减器,可用于密集波分复用系统中各信道的动态增益平衡。该器件采用电磁线圈驱动绕100微轴转动的微反射镜,运动部件行程极小。驱动电压为0～8V,工作范围0～35dB,动态响应时间小于2ms,插入损耗小于0．8dB,回波损耗小于-50．5dB。器件采用微细电火花加工技术制作,加工精度为微米量级。技术成熟,工艺简单,易于批量生产。采用有限元分析软件ANSYS对器件的结构建模,对电磁场及衰减曲线进行了理论分析,并与实测数据进行了比较,得出了相当满意的结果。     

A Novel Extrinsic Fiber-Optic Fabry-Perot Strain Sensor System Based on Optical Amplification

A novel extrinsic fiber-optic Fabry-Perot interferometric strain sensor system is demonstrated based on the simultaneous use of the amplified spontaneous emission and optical amplification. The improvement of 3～4 orders of magnitude in signal level can be achieved.     

Prototype Demonstration of Discrete Correlation Processor-2 Based on High-Speed Optical Image Steering for Large-Fan-Out Reconfigurable Optical Interconnections

We present a discrete correlation processor-2 (DCP-2), which is an optical processor with reconfigurability of interconnection patterns for large-fan-out optical interconnection systems. To our knowledge, there is no reconfigurable optical processor satisfying the requirements for large fan-outs such as high-speed reconfiguration of interconnection pattern, high optical efficiency, and high contrast ratio, because existing spatial light modulators (SLM#x0027;s) lack at least one of these features. The DCP-2 architecture fulfills the requirements by using a hybrid configuration composed of a high-speed image steerer and a spatial light modulator, which work in a complementary manner to shorten the setup time of the SLM. We constructed two kinds of prototype demonstrators based on this architecture. In the experiment, reconfiguration speed of the DCP-2 prototype with shift-invariant optical interconnections, in which a liquid crystal SLM cooperated with a two-dimensional acousto-optic beam deflector, was about 26,000 times faster than that of the standalone SLM at the cost of 50#x0025; energy loss by the deflector.     

基于黑色层纳米薄膜的可重构可见光滤波器

基于铁电材料的介电可调特性,提出一种新颖的基于黑色层纳米薄膜的可重构可见光滤波器,并比较了它与一维光子晶体滤波器反射光谱的可重构特性.实验结果表明,利用黑色层吸收非相干散射光可显著提高反射颜色对比度.当钛酸钡(BTO)薄膜的厚度从100 nm变为140 nm时,反射光谱的峰值波长由383.7 nm移动至501.2 nm...     

Fluorescent Biosensor Based on Hairpin DNA Stabilized Copper Nanoclusters for Chlamydia trachomatis Detection

Chlamydia trachomatis (C. trachomatis) is a kind of intracellular parasitic microorganism, which can causes many diseases such as trachoma. In this strategy, a specific hairpin DNA with the probe loop as specific regions to recognize C. trachomatis DNA with strong affinity was designed, and its stem consisted of 24 AT base pairs as an effective template for hairpin DNA-CuNCs formation. In the absence of C. trachomatis DNA, the detection system showed strong orange fluorescence emission peaks at 606 nm. In the presence of C. trachomatis DNA, the conformation of DNA probe changed after hybridizing with C. trachomatis DNA. Then, the amount of hairpin DNA-CuNCs was reduced and resulted in low fluorescence emission. C. trachomatis DNA displayed a significant inhibitory effect on the synthesis of fluorescent hairpin DNA-CuNCs due to the competition between C. trachomatis DNA and the specific hairpin DNA. Under the optimal experimental conditions, different concentrations of C. trachomatis were tested and the results showed a good linear relationship in the range of 50 nM to 950 nM. Moreover, the detection limit was 18.5 nM and this detection method possessed good selectivity. Finally, the fluorescent biosensor had been successfully applied to the detection of C. trachomatis target sequence in HeLa cell lysate, providing a new strategy for the detection of C. trachomatis.