Active polarization control for quantum communication in long‐distance optical fibers with shared telecom traffic

Abstract

a combination of radiated susceptibility plus conducted susceptibility. Sensors with cables of ECG equipments are so sensitive and open to be distorted. These induced current is then driving through electronics by conduction mechanisms. CONCLUSIONSABSTRACT: We experimentally demonstrate the compatibility of wavelength multiplexed active polarization stabilization for quantum communication in an optical fiber carrying telecom traffic. One of the feedback control channels contains a 9.953 Gb/s datastream generated from a BER meter. We verify the ability to transmit single-photons in the two opposite directions of a 23-km optical fiber spool, while maintaining their state of polarization stable and a classical BER in the feedback channel error-free, during 6 h of continuous operation.ABSTRACT: This letter deals with a GaAs monolithic microwave integrated circuit (MMIC) Doherty power amplifier (DPA) for X-band systems. To the best of authors' knowledge, it represents the first DPA realization in the X-band frequency range. Experimental results showed a 30-dBm saturated output power and a drain efficiency greater than 53% at 9.5 GHz. Moreover, in the 6-dB power back-off (from 18 to 24 dBm input power), an amplitude modulation (AM/AM) distortion lower than 1 dB is also demonstrated with an average efficiency greater than 50%.

Entanglement distribution over 150 km in wavelength division multiplexed channels for quantum cryptography

“…Compared to the experiment reported by Lim and co-workers [10], in which polarization entanglement is analysed sequentially at different wavelengths, we believe that energy-time entanglement is much better suited for this kind of applications as the associated analysis system is made of stand-alone devices. In other words, the latter do not necessitate any phase stabilization as a function of the wavelength [34], making it possible to analyze entanglement simultaneously in all the correlated channel pairs. Furthermore, other protocols could also benefit from such an approach, e.g., those exploring high-dimensional QC towards increasing the number of encoded bits per photon [23,35].…”

Quantum key distribution for 10 Gb/s dense wavelength division multiplexing networks

“…[17][18][19][20][21] Despite these advances, further studies are required to establish the true potential of QKD in DWDM 10 Gb/s networks.…”

Proof-of-principle demonstration of measurement-device-independent quantum key distribution using polarization qubits

“…Due to the random residual birefringence fluctuations in the fibers we employed an active fullpolarization control system based on two feedback signals wavelength-multiplexed with the single photons, thus stabilizing any polarization state transmitted through the fiber in the quantum channel wavelength, similarly to [27][28][29][30]32]. These two signals are generated from semiconductor distributed feedback (DFB) laser diodes located within Charlie's station as shown in the experimental setup (Fig.…”

“…In this paper we perform an experimental implementation of MDI-QKD using polarization qubits encoded on weak coherent states, as originally proposed by Lo et al [23]. The links between Alice (Bob) and Charlie are 8.5 km optical fiber spools, individually stabilized with automatic polarization control systems [27][28][29][30]. This is fundamental to guarantee a good fidelity between the chosen SOPs of the faint laser pulses sent by Alice and Bob, and the arriving SOPs after fiber transmission at the BSA.…”