Dissertação de Mestrado #631 – Pedro Henrique Grosman Alves – 23/10/2019

Research in optical communication through atmospheric links faces many challenges in seeking for reliable implementation. Coherent classical light, such as a laser beam propagating through the atmosphere, suffers a significant impact on signal quality due to atmospheric turbulence. Although there are several communication techniques to mitigate signal fading in classical light, any of these techniques do not eliminate the aberrations that come from several sources. Thus, it is worth to develop new techniques to soften even more the turbulence-induced perturbations. In this work, we study a modified experimental setup to mitigate turbulence-induced signal fluctuations, i.e., signal fading, on entangled photon beams, which lead us to a more stable communication. Twin-photons quantum states, spontaneously produced by parametric-down conversion, were used to demonstrate experimentally that an inversion of transverse coordinates of the correlation beam, is sufficient to partially eliminate the aberrations caused by turbulent airflow. Furthermore, we show that not only a coordinate inversion does mitigate turbulence effects, but it completely eliminates the wavefront tilt aberration. Our evaluation reveals that optical communication through atmospheric links could benefit from using quantum states of light.