时间:   2013年11月6日（周三）上午9：00—11：00

地点:   延长校区行健楼1018室

讲座:  轨道角动量光通信系统与器件

演讲者：Moshe Tur教授, 以色列特拉维夫大学

演讲者简介：Moshe Tur received the B.Sc. in Mathematics and Physics, from the Hebrew University, Jerusalem, Israel (1969), the M.Sc. degree in Applied Physics from the Weizmann Institute of Science, Rehovot, Israel (1973), and his Ph.D. from Tel-Aviv University, Tel-Aviv, Israel (1981). He is presently the Gordon Professor of Electrical Engineering at the School of Electrical Engineering of Tel-Aviv University, Tel-Aviv, Israel, where he has established a fiber-optic sensing and communication laboratory. He authored or co-authored more than 350 journal and conference technical papers with emphasis on fiber-optic sensing (with current emphasis on Structural health Monitoring, using fiber Bragg gratings and the Brillouin effect), polarization mode dispersion, microwave photonics, and advanced fiber-optic communication systems. Prof. Tur has strong international relations, including summer visits to: Stanford University, BellCore Laboratories, University of Strathclyde in Glasgow, Swiss Institute of Technology, Communication Research Laboratory of the Japanese Ministry of Post and Telecommunications, AT&T Research Laboratories, the University of Southern California. Prof. Tur is a Fellow of both the IEEE and the Optical Society of America.

讲座摘要(Abstract)：Internet data traffic capacity is rapidly reaching limits imposed by optical fiber   nonlinear effects. Having almost exhausted the available degrees of freedom to orthogonally multiplex data, the possibility is now being explored of using spatial modes of fibers to enhance data capacity. We'll discuss the viability of using the orbital angular momentum (OAM) of light to create orthogonal, spatially distinct streams of data-transmitting channels that are multiplexed in free space or in a single fiber. Over 1.1 kilometers of a specially designed optical fiber that minimizes mode coupling, 400-gigabits-per-second data transmission using four angular momentum modes at a single wavelength, and 1.6 terabits per second using two OAM modes over 10 wavelengths was demonstrated, as well as 100 Tb/s in free space. These demonstrations suggest that OAM could provide an additional degree of freedom for data multiplexing in future fiber networks. The talk will describe OAM modes, their (i) properties (ii) generation; (iii) multiplexing and demultiplexing and (iv) a few system experiments. Quite a few devices are required for successful transmission and networking of OAM beams and modes. The currently available ones will be mentioned along with their deficiencies and the need for better ones.