Projects per year
Single-mode optical ﬁbers are widely used for data transmission, and form the backbone of our communications infrastructure. However, these ﬁbers have a ﬁnite capacity, which we are approaching. The most promising solution to increase the capacity of optical ﬁbers is the use of spacedivision multiplexing (SDM), where several spatial paths in a single optical ﬁber are used to enable simultaneous data transmission of several independent data streams for each carrier wavelength. This thesis examines SDM using orbital angular momentum (OAM) modes, and linearly polarized (LP) modes. A special air-core optical ﬁber supporting stable propagation of OAM modes is characterized, and used in a communications experiment. This resulted in simultaneous transmission of 12 OAM modes in the air-core ﬁber, without the need of multiple-input multiple-output signal processing. Raman ampliﬁcation of OAM modes in the air-core ﬁber is explored, using diﬀerent pumping schemes, and is found to be a solution in order to amplify OAM modes in the transmission ﬁber. Finally, the complexity of SDM systems is addressed, through a novel SDM receiver structure, which signiﬁcantly reduces the number of components needed to receive an SDM signal. The receiver is demonstrated using a system based on LP mode multiplexing in a ﬁber supporting 3 modes.
|Place of Publication||Kgs. Lyngby|
|Publisher||Technical University of Denmark|
|Number of pages||75|
|Publication status||Published - 2018|