Entanglement protection of Ince-Gauss modes in atmospheric turbulence using adaptive optics

Abstract

In this paper, we describe the study of the faithful propagation of entangled orbital angular momentum states of light under atmospheric turbulence. The spatial mode is encoded in the Ince-Gauss modes that constitute a complete family of exact and orthogonal solutions of the paraxial wave equation in an elliptic coordinate system. Adaptive optics is employed to protect the entanglement from degradation, in which the threshold of turbulence strength could be enhanced for a reliable entanglement distribution. We find that the evolution of entanglements relies on ellipticity and shows the opposite trend when adopting adaptive optics. The turbulence strengths, at which the concurrences of various entangled states become zero, are different without adaptive optics but almost the same with adaptive optics. The trace of the density matrix is independent of the different ellipticity with or without adaptive optics. We believe that this investigation is useful for long-distance quantum communications and quantum networks using orbital angular momentum as information carriers.

Ince-Gauss Photons in Turbulent Atmosphere: Effect of quantum numbers on beam resilience

“…In this work, simulations of Helical Ince-Gauss beams were done, paying special attention to analysis of the robustness of the modes as information carriers according to the ellipticity parameter, concluding that it plays an important role on the performance of the modes, as well as the degree m parameter. Another study by Zhu et al was done [27] in which the robustness of entangled modes in turbulent atmosphere can be modified by the ε parameter. Comparing their results to the ones presented in this work, considering both the simulation and methods used, there was a good agreement on the obtained values when converting to the Fried parameter r 0 .…”

“…This characteristic makes them potential candidates for usage in applications involving optical vortex beams, particularly those regarding free space propagation. Besides few studies on FSO communication systems for these beams [25][26][27], Ince-Gauss (IG) beams have been used in applications such as OAM entanglement [28,29], optical tweezers [30] and have exhibited lots of intriguing phenomenon when propagating in different types of media like strongly nonlocal nonlinear media [31], elliptical core few-mode fibers [32], or even interacting with atoms [33].…”

Ince–Gaussian beams propagation through turbulent atmospheric medium

“…Later, many works have proposed other revolutionary methods to generate IGBs and Helical IGBs (Bentley et al 2006, Otsuka et al 2007, Ohtomo et al 2008, Aguirre-Olivas et al 2015, Ren et al 2015, Wang et al 2018, Jackin et al 2022. In recent years, a study on the effect of turbulent atmosphere on the IGBs propagation has been frequently conducted and its findings show that these beams exhibited lots of intriguing phenomenon when propagating in this medium (Eyyuboğlu 2014, Gu et al 2020, Zhu et al 2020. Hence, an analysis of the properties of IGBs propagating through turbulent atmosphere was done using a random phase screen setup and the split step propagation method (Andrews andPhillips 2005, Schmidt 2010) to avoid the calculation difficulties in analytical methods.…”

“…Recently, Castañeda et al (Narváez Castañeda et al 2022) have used the same methods to analyze the effects of the order, degree and ellipticity parameters on the robustness and the performance of the IGBs propagating through turbulent atmosphere. The faithful propagation of entangled orbital angular momentum states of Ince-Gaussian modes under turbulent atmosphere are described using an adaptive optics to protect the entanglement from degradation (Zhu et al 2020). Other studies were done about these beams to investigate the scintillation performance of IGBs in turbulent atmosphere.…”

The analysis of efficiency for high-dimensional quantum secure direct communications under atmospheric turbulence

“…For the OAM entangled photon pairs, Leonhard et al simulated the effects of two adaptive optical systems on the concurrence of the OAM entanglement with different OAM values under weak-medium turbulence intensities [41]. Then, Sorelli et al extended entanglement to high-dimensional Bell States by using similar methods [42], and recently, Zhu et al have studied the faithful propagation of entangled OAM states in the elliptic coordinate system with adaptive optics under atmospheric turbulence [43]. In this paper, we first calculate the performance and capacity of single photons QSDC under atmospheric turbulence, and also we analyze the security of the practical protocol under the cloning-based individual attack in the turbulent channel.…”