Air turbulence effects on performance of optical wireless communication with crosstalk in server backplane

Abstract

Free space optical interconnections (FSOIs) are anticipated to become a prevalent technology for short-range high-speed communication. FSOIs use lasers in board-to-board and rack-to-rack communication to achieve improved performance in next generation servers and are expected to help meet the growing demand for massive amounts of inter-card data communication. An array of transmitters and receivers arranged to create an optical bus for inter-card and card-to-backplane communication could be the solution. However, both chip heating and cooling fans produce temperature gradients and hot air flow that results in air turbulence inside the server, which induces signal fading and, hence, influences the communication performance. In addition, the proximity between neighboring transmitters and receivers in the array leads to crosstalk in the received signal, which further contributes to signal degradation. In this Letter, the primary objective is to experimentally examine the off-axis crosstalk between links in the presence of turbulence inside a server chassis. The effects of geometrical and inter-chassis turbulence characteristics are investigated and first-and second-order statistics are derived.

A vertical DIM lidar for refractive index structure parameter profiles estimation in low‐layer atmosphere

“…Due to the chaotic behavior of the turbulent atmosphere, stochastic processes such as temperature and pressure cannot be approximated as stationary during the measurements. Extensive studies have illustrated the significance of obtaining precise low‐layer $${C}_{n}^{2}$$ vertical profiles to evaluate the impact of atmospheric turbulence on the performance of photoelectric systems 2–4 . In this Letter, we propose an alternative $${C}_{n}^{2}$$ profile estimation approach that is both computationally inexpensive and capable of real‐time acquisition.…”

“…Extensive studies have illustrated the significance of obtaining precise low-layer C n 2 vertical profiles to evaluate the impact of atmospheric turbulence on the performance of photoelectric systems. [2][3][4] In this Letter, we propose an alternative C n 2 profile estimation approach that is both computationally inexpensive and capable of real-time acquisition.…”