Actas de congresos
Analysis Of Underwater Laser Beam Propagation For Undersea Communication
Registro en:
780319710
Conference Proceedings - Lasers And Electro-optics Society Annual Meeting. Publ By Ieee, Piscataway, Nj, United States, v. 8, n. , p. - , 1994.
2-s2.0-0028062644
Autor
Mazzuco Carlos L.
Mendes Leonardo S.
Pierre Jean
Weid V.D.
Institución
Resumen
The advent of the laser in 1960 has generated a new interest in the development of optical communication systems. Initially, the laser was used in atmospheric optical links, but these were extremely expensive. Later, with the development of the optical fiber, the great effort in optical communication was transferred to guided optical channels. However, there still are numerous unguided-channel optical systems under development for optical links up to about 25 km long. Our goal is to study underwater optical communication systems to control subsea equipment of offshore petroleum production systems. In this work, we study the effects experienced by a laser beam propagating through the turbulent ocean. The propagation of laser beams in turbulent media has been deeply studied by many authors. When an electromagnetic wave propagates through a turbulent medium, it is affected by several effects that distort the original signal. These effects are: attenuation, bending of the wave and random scattering, which causes many variations in the wave (amplitude, phase, angle of arrival). In this work, one first obtains the optical properties of sea water and determines the link ranges for the available laser's wavelengths. Then, environmental data is used to obtain the refractive index profiles with depths and its variations throughout the year. The propagation equation is used to describe the beam trajectories in different conditions and the effects of the variations in the refractive index are calculated in the form of deviations in the point of arrival. These deviations are compared to the platforms' movements to check if their amplitudes and frequencies are of the same order, an important point for the design of tracking systems. Finally, we discuss the systems configurations and performance in a simplified way. 8