查询词典 fiber-optic

With the support of a major research grant of Zhejiang Province (No. 001101027) and the Plan of Promoting Education of Excellence of Zhejiang University in the 21st Century, this dissertation is devoted to address the above problems and fabricate an L-band EDFA with low cost, high performance and technological innovation.First the mechanism of an erbium doped fiber amplifier is introduced. Various theoretical models based on classical rate propagation equations are summarized and compared for their applications. We use a modified numerical model based on the Giles model, which agrees with the experimental results well. This serves as the theoretical base for the whole thesis and will be used to optimize the characteristics of EDFAs. A novel method based on a map of noise figure and gain is proposed to analyze efficiently the dependence of the noise figure and gain for EDFAs on the EDF length and the pump power. The characteristics of various EDFAs are studied and compared.Secondly, some important parameters are introduced to describe the characteristics of EDFAs. The methods and the experimental setups for measuring the gain and noise figure of an EDFA are emphasized. We introduce how to measure the characteristics of each component of an EDFA, especially the gain and absorption coefficient of an erbium doped fiber.Thirdly, four types of simple and novel L-band EDFA structures with low noise, high gain and low gain ripple are proposed to satisfy the requirement of a DWDM system. They can be classified into two categories. In the first category, a single ASE pumping is served asa secondary pump. This category includes the following three types. Type: a new construction using a fiber Bragg grating in an unpumped EDF section at the input side. Type: a new structure of L-Band EDFA with two-stage pumps, which utilizes the forward ASE as a second pump.

本论文本着科技创新、服务于生产实践的精神，以设计价格低廉，性能优越、结构合理简单的L-band EDFA为目标，依托浙江省科技厅重大科学基金资助项目(001101027)和浙江大学振兴教育计划资助的全光网络的搭建—《光通信技术》课程实验建设项目，展开了如下工作：首先，介绍了掺铒光纤放大器的工作原理，归纳总结了基于速率方程基础的EDFA的各种理论模型，分析比较了各个模型的特点和适用场合，最终选择完善的Giles理论模型作为本论文分析设计EDFA的理论基础；针对实际实验条件提出了修正的EDFA模型的数值计算方法；创新地提出了增益—噪声系数全局分析法，直观有效地分析了EDFA的增益和噪声系数与掺铒光纤长度和泵浦功率的依赖关系，并对各种EDFA的性能作了全面的比较；第二，介绍了掺铒光纤放大器特性参数的定义与测量方法，重点介绍了噪声系数和增益系数的测量方法及实验装置；介绍了组成掺铒光纤放大器各组件的特性测量方法，重点介绍了测量掺铒光纤参数的方法和实验装置；第三，针对WDM系统对L-band EDFA谱平坦、低噪声、高增益的要求，我们创新地提出了四种不同的L-band EDFA结构，按设计思路可以分为两大类：一类是基于单抽运二级泵浦法，这一类包括在未泵浦掺铒光纤的输入端插入一根布拉格光纤光栅的两段L-band的EDFA的新结构；基于前向ASE光作为二级泵浦源推动下一级EDF工作的泵浦分配、两段级联L-band的EDFA的新结构；基于单根光纤光栅、泵浦分配、两段级联的EDFA；另一类则是基于同时应用前后向C-band ASE作二级泵浦源的双抽运法，如基于前后向ASE光作为二级泵浦源的三段级联L-band的EDFA的新结构。

To realize single longitudinal-mode of the fiber laser, a ring configuration is devised. The single longitudinal-mode operation is realized by using a fiber Bragg grating as wavelength-selective element and a unpumped 2m-loog erbium-doped fiber which can produce stading-wave saturation effects in the cavity, Its tunable wavelength range is 42 nm, the output power is more than 3.5 dBm and the stability is less than ±0.005 dB.

为了实现光纤激光的单纵模，提出了一种环形腔结构，采用可调谐光纤Bragg光栅作为波长选择器件，与2m未抽运掺Er光纤产生驻波饱和效应，在1.55m波长处形成42nm激光输出，输出功率大于3.5dBm，功率稳定性优于士0.005dB。

Spatial holeburning caused by ununiform widening of erbiumdoped fiber barricades the fully gaincontrolled amplification of laser with single wavelength. A novel configuration of automatic gainclamped optical erbiumdoped fiber amplifier is presented, and a high-birefringence fiber Bragg grating is used to generate pumping lasers, peaks of which are written at 1549.3 nm and 1549.83 nm with a wavelength spacing of 0.53 nm.

掺铒光纤非均匀展宽引起的空间烧孔现象导致单波长激光并不能完全控制放大器增益，提出了一种新颖的自动增益控制掺铒光纤放大器的结构：即采用高双折射光纤布拉格光栅产生抽运光，其写制光栅的波峰对应的波长分别为1549.3 nm和1549.83 nm，波长间隔为0.53 nm。

It was showed that pectenolone and pectenoxanthin were all found in Gonads, hepatopancreas, mantle and gill, among of them, ovary, hepatopancreas and gill possessed more carotenoid than other tissues, but no carotenoids were found in the white muscles of Yesso scallops. Hepatopancreas contains a variety other carotenoids some kind of other not identified beside pectenolone and pectenoxanthin. The result also showed that the Yesso scallop with orange muscle had more the carotenoids in a variety of tissues than the common, and the female more than the male.4 Impacts of carotenoid accumulation on morphological structure and chemical composition in orange muscle of Yesso scallopThere was no difference between the orange and white muscle obserced by conventional HE staining, while musclular fiber type and matrix density in the orange muscle was different from white ones by the TEM observation of ultra-thin slices, and there were three musclular fiber types, among of them, the loose muscular fiber was orange muscle specifically.

利用HPLC法对橘红/白色闭壳肌虾夷扇贝各组织中含有的类胡萝卜素种类和含量，结果表明，虾夷扇贝在性腺、肝胰腺、外套膜、鳃丝中均含有类胡萝卜素pectenolone和pectenoxanthin，白色闭壳肌中未检测到类胡萝卜素，其中肝胰腺除上述两种类胡萝卜素外，还含有其他多种未鉴定的类胡萝卜素；在各组织中，雌性性腺、肝胰腺、鳃丝中类胡萝卜素的含量较高；橘红色闭壳肌虾夷扇贝各组织中的类胡萝卜素含量高于白色闭壳肌虾夷扇贝；雌性虾夷扇贝中的类胡萝卜素的含量高于雄性。4累积类胡萝卜素对虾夷扇贝闭壳肌的形态结构和化学成分的影响本文对橘红色闭壳肌进行了常规HE染色切片观察，并未观察到异常现象；超薄切片透射电镜观察发现橘红色闭壳肌在肌纤维类型及基质密度等方面有别于白色闭壳肌，在橘红色闭壳肌中有三种肌纤维，其中疏松型肌纤维为橘红色闭壳肌特有。

Fiber grating coupler has good wavelength selection characteristic of optical fiber grating as well as multiport advantage of fiber coupler. These features make it easy to realize allfiber optical add/drop multiplex.

光纤光栅耦合器具有光纤光栅良好的波长选择特性和光纤耦合器的多端口特点，易于实现全光纤的光波分插复用。

MORs of PP/wood fiber, PS/fiber, and PE/fiber composites with coupling agent added were raised by 18.4%, 37.1%, and 42%, respectively, compared to those without coupling agent.

结果表明，添加耦联剂的纤维／聚丙烯、纤维／聚乙烯和纤维／聚苯乙烯复合材料的弯曲弹性模量分别比未添加耦联剂的复合材料的弹性模量增加了18.4%，37.1%，42%。

This fiber could be carbonized or activated into carbon fiber and activated carbon fiber material with wide use and good capability.

该纤维可进一步炭化或活化加工成用途广泛、性能优良的破纤维和活性破纤维材料。

In the process of producing bamboo fiber, it is a good assistant degummed instrument.6. Mechanical process is very important in the manufacturing of bamboo fiber, it is a key step to degumming from the fiber.

6机械加工在竹纤维的制取过程中尤为重要，它是将胶质从纤维上脱除的关键步骤，同时采用机械牵伸机对纤维细度的改进有利，但是这种方法仍然需要进一步的改进。

Polycrystalline alumina bulk fibers, fiber felts, fiber board and fiber special shaped products.

多晶氧化铝系列纤维棉、毡、板和异型制品。

Then after analysising each characteristics of phosphate glass material, the fiber rod-in-tube by invaginating core rod, inside cladding and outside cladding is used to fabricate the Er/Yb phosphate glass fiber successfully by polishing and vacuumizing fiber rod-in-tube.

利用玻璃浇注方法得到增益玻璃芯棒，然后对芯棒进行抛光处理，并且采用芯棒、内包层玻璃管和外包层玻璃管套接的方法制作光纤预制棒，将制作的预制棒进行了粘度等测试，并抽真空加热到一定温度条件下成功地拉制出芯径5μm，外包层65μm的单模铒镱共掺磷酸盐增益介质玻璃光纤。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。