【作者】 赵志勇；

【导师】 张玉书；

【作者基本信息】 吉林大学 ， 微电子学与固体电子学， 2004， 博士

【摘要】 光纤通信已成为通信领域最为活跃的技术，它与卫星通信、移动通信形成现代通信技术的三大主要发展方向。目前，各种通信业务不断涌现，特别是因特网业务的飞速发展，造成通信容量的激增，因此大容量、高速率光纤通信系统的建设就成为一项紧迫的任务。光纤光栅器件的出现为大容量高速率通信系统的进一步发展提供了可能。光纤光栅是光纤纤芯折射率受到周期性微扰而形成的一种新型全光纤无源器件。由于具备与光纤系统兼容、插入损耗低、易于制作、体积小、成本低廉等优点，光纤光栅在光纤通信和传感领域均有着广阔的应用前景。因此，从第一支光纤光栅的研制成功到现在，光纤光栅的制备和应用一直是人们关注的热点。chirped光纤光栅是指光栅的光学周期(光栅有效折射率neff与折射率微扰周期Λ的乘积)沿光栅轴向逐渐变大（小）的一种光纤光栅。在chirped光纤光栅轴向不同位置可反射不同波长的入射光。所以chirped光纤光栅具有宽的反射带宽，在反射带宽内具有渐变的群时延等其它类型的光纤光栅所不具备的特点。这些独到的特点使chirped光纤光栅在光纤通信和传感领域有着独到的应用，如滤波器和色散补偿器等。tilted 光纤光栅是指光栅的条纹与光纤轴向存在一定夹角的光纤光栅。这个夹角的存在使光栅内出现了多种模式耦合，也使得tilted 光纤光栅具有许多特殊性质，如较低的Bragg反射等。这些性质使tilted 光纤光栅具有特殊的应用。本论文对chirped光纤光栅(包括chirped取样光纤光栅)和tilted 光纤光栅的工作原理、制备、性能和应用作了深入系统的研究，工作主要有以<WP=149>下几点：本论文中采用相位掩膜法制作出了高质量的chirped光纤光栅，即利用chirp相位掩膜板和光纤掩膜板一次平移法（本实验室的专利技术）制作chirped光纤光栅。我们用这种方法在普通单模光纤中作出了100mm长的切趾线性chirped光纤光栅；光栅反射率，在0.4nm带宽内具有线性的群时延，群时延斜率即光栅的色散值为－2403ps/nm，时延振荡。该光栅已达到实用化要求，可用于补偿10Gbit/s系统中140km长普通单模光纤的色散，目前处于国内领先水平。另外，我们利用电阻线圈加热方法和平面板弯曲法在光纤Bragg光栅上制作了线性和非线性的chirped光纤光栅，而且在保持光栅中心波长不变的情况下，调节光栅的chirp量；利用平面板弯曲法和腐蚀法分别在均匀取样光纤光栅上制作了线性和非线性的chirped取样光纤光栅。我们首次提出利用一块宽带chirp相位掩膜板和程控扫描曝光技术制作具有不同光谱形状的chirped光纤光栅滤波器。对于某一给定的光谱，我们利用自主开发的软件对其进行解析，将光谱中的波长，强度等函数转换成扫描曝光过程的控制函数，然后在程序控制下进行扫描曝光制作chirped光纤光栅，制备的光栅光谱与给定的光谱基本一致。实验中，我们制作了在40nm带宽内具有相同反射率的chirped光纤光栅滤波器。特别的，我们针对EDFA的ASE谱成功制作了基于chirped光纤光栅的增益平坦滤波器，在30nm带宽内，增益平坦度小于±0.3dB，达到国际先进水平。这种方法方便灵活，可以根据不同的增益谱线迅速调整参数，制作出相应的增益平坦滤波器，这项技术正在申请国家发明专利。我们首次提出利用一块Bragg相位掩膜板和旋转扫描程控技术制作具有不同光谱形状的基于tilted光纤光栅的滤波器。在利用掩膜板旋转法制作了tilted光纤光栅时，发现随着倾斜角度的增大，tilted光纤光栅的Bragg反射峰向长波方向移动，同时反射率逐渐下降。在此基础上，我们提出在制作tilted光纤光栅时倾斜角连续增大，那么对应于不同倾斜角的反射峰就级联成一个较宽的反射带，与此同时，调整曝光量就可以得到符合设计要求的宽带tilted光纤光栅。实验中，我们利用一块Bragg相位掩膜板和旋转扫描程控技术制作了带宽为5nm，带内反射率均为90％的宽带tilted光纤光栅滤波器，这项技术正在申请国家发明专利。另外我们用平面板弯曲法制作了具有宽带透射谱的chirped tilted光纤光栅。 <WP=150>4、 我们首次提出利用光纤Bragg光栅或chirped光纤光栅制作基于功率测量的温度不敏感的应变传感器。实验中，我们将光栅的前段粘在一块宽度远远大于光纤直径的石英板上，其余部分裸露或用腐蚀等方法使其直径逐渐变小，然后用功率计或光电探测器检测光栅的功率。当光栅受力时，由于石英板宽度远大于光纤直径，所以粘在石英板上的光栅段对应波长不会变化，而其余部分向长波移动，引起光栅带宽和光功率变化。在一定范围内，光功率变化与应力成线性关系，可以用来测量应力大小，实验中我们得到较高的传感器灵敏度为71μw/N。或者用腐蚀等方法使整支光栅的直径逐渐减小，施加应力时光栅带宽变宽，光功率也会发生变化，同样可以检测应力大小。由于石英板与光纤具有相同的膨胀系数，所以当温度改变时，光栅的带宽不变，因此光功率不会改变。这种传感器结构简单，解决了温度应力的交叉敏感问题，而且基于功率测量，降低了成本。这项技术正在申请国家发明专利。chirped光纤光栅和tilted光纤光栅都是性能优异的无源器件，随着新材料光纤和新的光栅制备技术的发展，这两种光栅可能具有更多的特性及?更多还原

【Abstract】 Optical fiber communication is the most active technology of communication field. Optical fiber communication, satellite communication and mobile communication are the three main orientations of modern communication technology. At present, plenty of communication business continuously emerges, especially fast development of Internet induces rapid increase of communication capacity. Thus, it is necessary to establish large-capacity and high-speed optical fiber communication system. Fiber gratings provide possibilities for the further development of large-capacity and high-speed optical fiber communication system. Fiber grating is a new kind of all-fiber passive device that results from that the refractive index of optical fiber core is periodicity microperturbation. Because of the excellent properties such as compatible with optical fiber, easy fabrication, little insert loss, small volume and low price, fiber gratings have wide application in optical fiber communication and sensor field. Thus, <WP=152>since the successful fabrication of first fiber grating, the fabrication and application of fiber gratings is central issue of interest all along. Chirped fiber grating is one type of fiber gratings whose optical period (product of grating’s effective refractive index and refractive index microperturbation’s period). Light with different wavelength is reflected at axial different point of chirped fiber grating. So chirped fiber gratings have broad reflection bandwidth. The group delay in chirped fiber grating reflection bandwidth changes gradually. These properties are what other type fiber gratings do not have. It is these unique properties that make chirped fiber gratings have unique applications both in optical communication and sensor field, such as filters and dispersion compensators. Tilted fiber grating is another type of fiber gratings with an angle between the fringes and the normal to the fiber axis. There are many kinds of coupling in tilted fiber grating because of existing of the angle. The special properties of tilted fiber gratings, such as lower Bragg reflection, make the gratings have special applications.The work of this thesis is deeply studying the principle, fabrication properties and applications of chirped fiber gratings (including chirped sampled fiber gratings) and tilted fiber gratings. The main achievements of this thesis are shown as following:High quality chirped fiber gratings were fabricated by the method of using phase mask, in which we used a chirped phase mask and once scanning explore technique to fabricate chirped fiber gratings. In experiment, a 100-mm apodized linearly chirped fiber grating was obtained that has more than 99% reflectivity, linear group delay in reflection bandwidth of 0.4nm, dispersion of about -2403ps/nm, ripple of delay of less than +/-20ps. The grating can compensate 140 km long fiber in 10Gb/s system, and it has been advanced in the nation. In addition, the linearly or nonlinearly chirped fiber gratings with fixed wavelength centers were fabricated by the methods of heating coils and bending plate using fiber Bragg gratings; the linearly or nonlinearly chirped sampled fiber gratings were also obtained by the methods of fiber etching and bending plate using uniform sampled fiber gratings.We firstly proposed to fabricate chirped fiber grating filters with different designed spectra using a wideband chirped phase mask and scanning explore technique. The designed spectrum of the filter was analyzed using the software (we reserved the copyright). Then the functions of the wavelength and intensity of the spectrum were converted to the controlling function during the explore process. The chirped fiber grating with spectrum same as the designed filter was fabricated by scanning explore controlled by the function. <WP=153>In experiment, the chirped fiber grating with uniform reflectivity in the range of 40 nm was obtained. Particularly, we successfully fabricated EDFA gain flattened filters (GFF) based on the chirped fiber gratings using the method. The v更多还原