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学术报告通知应校学术委员会和信息光子学与光通信国家重点实验室邀请，加拿大拉瓦尔大学（Université Laval）Sophie LaRochelle教授来我校进行学术访问，并作学术报告。报告题目：Optical fibers for OAM mode transmissions（适合光子轨道角动量模式传输的光纤设计）主讲人：Sophie LaRochelle教授主持人：张晓光教授（校学术委员会委员）时间：2014年11月7日（周五）上午9:00-11:00地点：校办公楼501报告厅报告摘要：In today’s information world, people and devices worldwide are constantly exchanging data through the cloud. This increased connectivity has spurred a quest for high capacity communication systems that must now overcome the fundamental capacity limit set by noise and nonlinear effects in single mode fibers. In this context, spatial division multiplexing (SDM) is currently emerging as the next wave of optical communication systems, allowing capacity scaling by orders of magnitude. SDM relies on transmissions of orthogonal modes in few mode fibers (FMF), sometimes in combination with a multi-core approach. A family of modes that could be used to decrease cross-talk in SDM links, and reduce digital signal processing requirements, is the family of modes carrying orbital angular momentum (OAM modes). Contrary to traditional LP modes that are degenerate combination of vector modes, OAM modes correspond to true fiber eigenmodes. In this talk, we will review the properties of OAM carrying modes in optical fibers. An important performance indicator in these fibers is the effective index difference between vector modes of a given mode group. We will describe three designs of OAM fibers to maximize the effective index difference and the number of OAM modes. The first one is an inverse parabolic graded index fiber (IPGIF) that supports six OAM states in addition to the fundamental mode. We will describe characterization results using FBG writing to measure index change. We will discuss efficient OAM mode excitation, present loss measurement results and discuss transmission in a 1 km fiber length. The second fiber has a ring index profile with a hollow central section that supports up to 36 OAM states. Finally, the third fiber design has a similar ring index profile but it is an all silica fiber (without holes). We discuss trade-offs in the number of modes, effective index separation and propagation loss in these ring designs. Lastly, we will briefly present the Center for Optics, Photonics and Lasers (COPL). We will describe its fiber fabrication facility and the testbeds of the optical communication laboratory. We will discuss opportunities for collaboration, student exchange and graduate studies. 校学术委员会信息光子学与光通信研究院信息光子学与光通信国家重点实验室2014年11月3日主讲人简介.docx http://portal.bupt.edu.cn//html/main/col51/2014-11/03/20141103095436793974734_1.html

学术报告通 知：Optical fibers for OAM mode transmissions

学术报告通知：Optical fibers for OAM mode transmissions