Improved Two-way Phase Coding: Involving Quantum Key Distribution Utilizing Fully Polarization Maintaining Optical Fiber

Quantum Key Distribution (QKD) system is capable of generating secrete keys between two parties and enables them to sense the presence of any third party providing unconditionally secure communications. During the development process of constructing the enhanced fully polarized QKD configuration, few problems were confronted and solved. The developed optical structure proved to have auto-compensation in terms of photons polarization because of utilization of polarization maintaining fiber and Faraday mirror. It was also observed that phase coding scheme is implementable for QKD over 100 km long of optical fiber with high visibility, trusted system fidelity and low QBER.