2023/05/18 by Muhammad Abdullah Butt, Butt, M. A. T., P. Roth +17
Engineering · #FOS: Physical sciences #Optical Network Technologies #Photonic Crystal and Fiber Optics #Photonic and Optical Devices #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2305.11220
openalex publication_date 2023/05/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Polarization-preserving fibers maintain the two polarization states of an orthogonal basis. Quantum communication, however, requires sending at least two nonorthogonal states and these cannot both be preserved. We present a new scheme that allows for using polarization encoding in a fiber not only in the discrete, but also in the continuous-variable regime. For the example of a helically twisted photonic-crystal fibre, we experimentally demonstrate that using appropriate nonorthogonal modes, the polarization-preserving fiber does not fully scramble these modes over the full Poincaré sphere, but that the output polarization will stay on a great circle; that is, within a one-dimensional protected subspace, which can be parametrized by a single variable. This will allow for more efficient measurements of quantum excitations in nonorthogonal modes.