The dual - core air - guided photonic bandgap fiber couplers are designed and decoupling phenomenon has been found . coupling properties of the pbgfs with two adjacent air holes as fiber cores are analyzed . the decoupling point , where there is no 对具有两个相邻纤芯的空气传导光子带隙光纤的传导模式和耦合特性进行了理论分析,在所分析的结构中发现了无耦合点,在该波长处两个相邻纤芯之间不发生能量转移。
The method also has the desirable feature of time saving and operator bias removing . the technique can be applied for the measurement of the outside diameter , the core diameter , or the core concentricity of hollow - core optical fibers , so as to eval - uate fibers 这个技术可以测量出空芯光纤的纤芯直径、包层直径、纤芯的不圆度、包层的不圆度以及纤芯/包层同心度误差，从而用来评估空芯光纤的质量。
The new fiber laser , including photonic crystal fiber ( pcf ) laser and multi - core double - clad fiber laser , was analyzed . one of novel structure . dcf laser that will be used into high power output was put forward based on the theoretic analysis 分析了新型光纤激光器(如光子晶体光纤激光器及多纤芯双包层光纤激光器)的基本原理及发展现况，设计了一种新型可实现高功率输出的双包层光纤激光器结构，并从理论分析出发给出其工作原理及制作方法。
During the accelerated thermal aging and ultraviolet radiation aging of pmma which is used as the core materials of fiber in pof , it was found that the relative permittivity of pmma decreased significantly to approximately equal to its square refractive index 摘要实验中观察到用作塑料光纤纤芯材料的纯有机玻璃（聚甲基丙烯酸甲酯）在加速热老化和紫外老化过程中其相对电容率急剧下降至大约等于其折射率的平方，即有机玻璃由极性聚合物变为非极性聚合物（ “全去偶极子极化”现象） 。
Point diffraction interferometer - a physical idea , is invented by smartt and strong in 1972 , advanced by smartt and steel , and used to test astronomical telescope , it has simple structure and has not special demand to source . recently . with the development of fiber ' s manufacture and coupling technology . the simple modern fiber ' s center is smaller than before , this make it possible to progress fiber point diffraction interferometer ( pdi ) , in addition to test convergent wavefront , it can test the reflective concave . the excellence of pdi is that it does not need standard mirror . in intereference testing , the standard mirror is the main reason which limit the improvement of precision , pdi can avoid difficulty to provide the wide future for high precision testing . pdi , which produce the standard sphere wavefront , is an instrument which realize the phase shifting with piezoelectric transducer ( pzt ) , and collect the interferogram with ccd , in this paper , a adjusting methord is described , then data processing is obtained 点衍射干涉仪这一物理思想，早在1972年smartt和strong就已发明，由smartt和steel做了进一步发展，并成功的用于检测天文望远镜，它结构简单，对光源没有特殊要求，近年来，由于光纤制造工艺以及耦合技术的发展，单模光纤纤芯不断缩小，为光纤点衍射干涉仪得以发展提供了前提条件，该干涉仪由激光照明，除了检测会聚波前外，还可以用来检测反射凹球面，进而应用到单个面形的检测；另外，光纤点衍射干涉仪最大的优点是不需要标准镜，在干涉检测中，标准镜是检测精度受限的很大原因，光纤点衍射干涉仪能绕开这一难度，为进行高精度的光学检测提供了广阔的前景。
Splicing between single - mode fiber and pcf are theoretically and experimentally investigated . the fiber bragg grating is written in grapefruit pcf . the multi - wavelength resonances are observed in the grating , and theoretical analysis shows that this phenomenon is caused by the resonances between core modes and cladding modes 建立了光子晶体光纤和普通光纤的熔接方法,在柚子形光子晶体光纤上写制了布拉格光栅,观察到多波长谐振现象,理论分析表明这是由于纤芯基模和包层模之间的谐振造成的。
But the core and na of ld output fiber is larger than that of double cladding fiber ' s inner cladding , it is important to analyze the ray propagating and focusing . the intensity distribution of multi - mode fiber is analyzed based on our experiments . and the optimum coupling efficiency is discussed between two multi - mode fiber , especially for the condition that core radius and na of output fiber are larger than that of input fiber 接着根据输入输出光纤的纤芯直径和数值孔径的不同，分四种情况分析了两光纤之间的耦合效率，着重分析了第四种情形，给出耦合效率的数值模拟曲线，在数值计算中用到了上面得出的输出光纤端口的光强分布，最后实验验证以上的分析。
Before plastic optical fiber widespread application , each kind of plastic optical fiber coupler must be used surely , at present the important method to manufacture the plastic optical fiber coupler is fused elongated taper . if adopt this kind of method , the conversion efficiency between the core modes and the cladding modes is low . one of the methods to solve that is 在塑料光纤广泛应用之前必然运用到各种塑料光纤耦合器,目前熔融拉锥法是制备塑料光纤耦合器的重要方法,然而此种方法存在纤芯模与包层模的转换效率比较低的问题,解决这问题的一种方法是对塑料光纤进行热预拉锥。
A laser diode with 976nm center wavelength and 2 . 03w maximum cw output power is pumping unidirectionally through the couple - imaging system on a double - clad yb - doped silica fiber with a yb - concentration 0 . 65 mol % circular inner core , a d - shaped inner clad , and 15m length by f - b cavity . the center wavelength of the fiber laser is 1130nm , and the maximum cw output power is 130 . 7mw . an optical - to - optical conversion efficiency of 42 % and a slope efficiency of 63 . 4 % are obtained 用中心波长976nm 、最大连续输出功率为2 . 03w的ld泵浦源，通过成像耦合系统，单端直腔式泵浦纤芯掺杂浓度为0 . 65mol % 、内包层截面形状为d形、长度为15米的双包层掺镱石英光纤，实现了中心波长1130nm 、最大功率为130 . 7mw的连续激光输出，光纤激光器的光光效率为42 . 0 % ，斜效率达到63 . 4 % 。
