Data transmission and electrical powering flexibility for cabled ocean observatories

Cabled ocean observatories share the need for both an efficient means of transmitting data to shore and a reliable source of electrical powering. Standard telecom undersea amplifiers offer the potential for tremendous capacity, but in some cases may not be optimal for low data rate or small capacity ocean observatory needs. Amplifier designs can be tailored for specific capacity requirements and can be further customized to support transmission using other-than-telecom-grade terminal transceivers. As a clear channel device, an EDFA can support a wide variety of data formats and bit rates. Multiple amplifier designs can operate simultaneously in the same repeater housing using the same single line-current feed. Optical add-drop multiplexing can be implemented to further enhance the flexibility and bandwidth utilization in these applications. A deep understanding of transmission design, simulation, and modeling can be leveraged to optimize the amplifier design and transmission performance for each specific ocean observatory need. Cabled ocean observatories typically use permanently-powered fiber-optic undersea cables for the transmission of data and electrical power. The undersea telecom industry has off-the-shelf products available and qualified for deepwater use that can be combined to support ocean observatory applications with unique powering and transmission requirements, including functions demanding much higher power than basic, low data rate sensor functions. This paper will review the basics of repeatered and nonrepeatered undersea fiber-optic transmission systems and provide summary descriptions of a number of qualified fiberoptic products relevant to cabled ocean observatories. Several architectures will be reviewed that make use of the above elements providing component and design option information for ocean observatories.