【作者】 王敏锋；

【导师】 翁梓华；

【作者基本信息】 厦门大学 ， 测试计量技术及仪器， 2008， 硕士

【摘要】 随着现代社会对信息传输容量和速度要求的不断提高,人们对现有的通信体系提出了更高的要求。光纤通信由于具有许多优点,如巨大的传输带宽、极低的传输损耗以及抗强电磁干扰等而得以快速发展。随着光纤通信技术的进步和密集波分复用(DWDM)系统的应用,全光交换已经成为当前全光网络的发展趋势,而光开关是全光网络的关键器件。光开关可以应用在全光网络的光插/分复用技术、光交叉连接技术和密集波分复用技术等方面,光开关的研制已经成为光通信领域研究的热点。本文主要依据磁光材料的法拉第效应设计了1×2磁光开关。其主要包括了线偏振光光路、电路和磁路及磁光开关时间测试等部分。本文的主要研究内容如下:(1)偏振光光路。磁光开关光路是全光纤磁光开关的核心部分,磁光开关的光路设计主要根据磁光材料的法拉第效应和线偏振光的性质。磁光开关的偏振光光路主要包括了偏振分束器、偏振合束器、YIG晶体等器件。本论文进行了对偏振分束器和合束器的方案选择,YIG磁光晶纤的后期处理,并针对线偏振光在光路中的耦合、偏振及损耗,做了理论分析和实验,对光路进行了对准耦合和测试。(2)电路和磁路。磁路设计是磁光开关时间的关键。通过电路触发产生的瞬时磁场改变线偏振光的状态,决定磁光开关的开和关。本论文设计了磁场结构一和二。磁场结构一依据磁光调制器的设计方案并结合课题所需要求进行优化,用本实验设计的纳秒脉冲进行触发。磁场结构二采用线圈型磁场结构,用AT89S52和MC33886芯片进行触发。本章主要焊接了单级和级联纳秒脉冲电路、磁场的模拟和触发信号的检测。(3)磁光开关时间测试。全光网络中光开关的开关时间是最重要指标之一。磁光开关时间可以通过光电探测器进行测试。本章通过实验测试磁光开关时间,并进行方案的优化,最后测试到切换时间为1.443微秒。更多还原

【Abstract】 With more demands of capacity and speed in transmission in current communication systems, a higher system was put forward. Optical communication system is developed apace because it has so many merits such as tremendous transmit bandwidth, very low transmit losses and anti-interfere of strong electromagnetism. All optical exchange scheme has been the trend of modern optical network with the development of optical communication system and application of Dense Wavelength-Division Multiplexing (DWDM), optical switch is the key element of all optical network (AON).The optical switch, which are used in Optical Add/Drop Multiplexer (OADM), Optical Cross Connect (OXC) and DWDM etc., is the key consideration in AON. The research and fabrication of optical switch become the hotspot in the optical communication.1×2 magneto-optical switch is designed in this paper, which is based on Faraday effect, and contains of the linear polarized light routes, electrocircuit and magnetic field and test of the switching time. The following are the main research contents:(1)The linear polarized light routes. The linear polarized light routes are the core of the magneto-optical switch, which comprise Polarization Beam Splitter (PBS), Dual Polarization Beam Combiner (DPBC), and Yttrium Iron Garnet (YIG) and so on. The selection of the elements of PBS and DPBC, the post-process of YIG magneto-optical single fiber were done in this paper, and did analysis and experiment on the coupling, insert-loss and polarization of the linear polarized light. At last, the whole optical routes were tested and leveled.(2)Electrocircuit and Magnetic field. The magnetic field is key component of magnetic field, trigged by the electrocircuit, which decides the switching time. The design I and II were introduced in this paper. The design I borrowed ideas from magneto-optical modulator, which contains nanosecond impulser. The design II adopted the windings and was trigged by AT89S52 and MC33886. The nanosecond implusers were fabricated, the magnetic field was simulated by ANSYS and the trigger circuits were tested.(3) The test of the switching time.The switching time is one of the most important specifications in AON. The switching time was tested by photoptical detector. The switching time was 1.443μs in the experiment at last.更多还原