A Low-cost Four-degree-of-freedom Motion-platform for Ship-borne Free Space Laser Communication

Abstract

<span style="font-size: 11pt; font-family: "Times New Roman"; mso-fareast-font-family: 宋体; mso-ansi-language: EN-GB; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-GB">Free space laser communication (FSOC) has been an emerging technology that is deployed in the marine ship communication field for enabling high-quality communications among moving ships due to its high anti-EM interference capability and good security. However, the system typically requires six dimensional supports of Acquisition, tracking and pointing in the moving environment, which is rather expensive. In this paper, we propose a novel four-degree-of-freedom solution based on the law of motion of the ship in wind waves derived from linear system theory; the solution uses a horizontal, a vertical and two rotating motions to simulate the laser movement caused by ship movement in the wind waves. To the best of our knowledge this is the first effort in this field; our approach significantly reduces the complexity and cost of the six-dimension based solution. Our experimental results demonstrate a realization of laser movement caused by ship roll movement in the wind waves, and verify the convenience and accuracy of the simulated ship-borne free space optical communication system.</span&gt