Engineering Entangled Photons for Transmission in Ring-Core Optical Fibers

The capacity of optical communication channels can be increased by space division multiplexing in structured optical fibers. Radial core optical fibers allows for the propagation of twisted light–eigenmodes of orbital angular momentum, which have attracted considerable attention for high-dimensional quantum information. Here we study the generation of entangled photons that are tailor-made for coupling into ring core optical fibers. We show that the coupling of photon pairs produced by parametric down-conversion can be increased by close to a factor of three by pumping the non-linear crystal with a perfect vortex mode with orbital angular momentum ℓ, rather than a gaussian mode. Moreover, the two-photon orbital angular momentum spectrum has a nearly constant shape. This provides an interesting scenario for quantum state engineering, as pumping the crystal with a superposition of perfect vortex modes can be used in conjunction with the mode filtering properties of the ring core fiber to produce simple and interesting quantum states.

STUDY OF METHODS FOR ENSURING INFORMATION INTEGRITY IN INFORMATION SYSTEMS WITH OPTICAL COMMUNICATION CHANNELS

The relevance of the work lies in the fact that the number of information systems with optical communication channels is increasing. However, for such systems, the optimal method for ensuring the integrity of information has not been identified. The purpose of the work is to identify the best method for ensuring the integrity of information in information systems with optical communication channels. This article discusses methods for ensuring the integrity of information at the stages of storage and transmission of information. The main method for ensuring the integrity of information at the storage stage is the data backup method. Parallel information transfer is the main method at the stage of information transfer. As a result of the study, the following conclusion was made: to ensure maximum security of information integrity, it is necessary to apply an integrated approach and use immediately both data backup and protection methods at the stage of information transfer.

A Holistic Survey on Disaster and Disruption in Optical Communication Network

Background: This paper is a review of optical fiber communications and also presents the different types of disasters and different protection schemes to combat these disasters. In the optical communication network, the failure of a network caused by disasters (e.g. predictable disaster, unpredictable disaster, Intentional attacks) leads to the failure of several optical communication channels and huge data loss. Most of the previous works on optical network survivability assume that the failures are going to occur in future, and the network is made survivable to ensure connectivity in events of failures. With the advancements in technology, the predictions of tornados, cyclone and landslides are becoming more accurate by using some early warning systems. Objective: Significant improvement in optical communication network survivability can be achieved using our proposed protection scheme in the event of a major earthquake, cloud burst and landslides. Conclusion: The review concludes that a large amount of data could be lost even if there is a very short disruption in the optical backbone network.

Perspective Methods of Transferring Information via Optical Communication Channels

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