Polarisation

Jochen Pade

Nelson Jesus Muga, Mariana F. Ramos, Sara T. Mantey +2 more

This study presents a theoretical model for polarisation manipulation using electronic polarisation controllers (EPCs) based on fibre squeezing. A method to calculate the EPC configuration in order to transform between two arbitrary states of polarisation (SOP) is presented. After, a technique to deterministically generate four SOPs for use in polarisation‐encoded quantum communication systems is proposed. Moreover, the effectiveness of the proposed technique is experimentally assessed through the generation of two pairs of orthogonal SOPs. The experimental implementation used an field programmable gate array (FPGA) board to electrically control the four waveplates of the EPC, reaching a rate of 500 qubit/s. Results show that this polarisation generation process is intrinsically stable, demonstrating its potential for practical implementations of polarisation‐encoding quantum key distribution systems using the BB84 and B92 protocols.

A. Hidayat, B. Koch, Vitali Mirvoda +4 more

Automatic endless polarisation control with a commercial LiNbO3 polarisation transformer is reported. The controller is able to track worst-case endless 5 krad/s polarisation rotations with maximum polarisation and intensity errors of 0.17 rad and 0.73%.

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G. Vilela de Faria, João Pedro Ferreira, GUILHERME BARRETO XAVIER +2 more

Real-time polarisation control schemes employing two multiplexed non-orthogonal reference signals are shown to provide complete control of multiple polarisation states for polarisation encoded quantum communications with negligible added noise in the quantum channel. The robustness of the control schemes to polarisation mode dispersion and induced penalties are simulated and discussed.

Jochen Pade