Optical architecture and interface lightguide unit for fiber-to-the-home feature of the AT&T SLC Series 5 carrier system

The subscriber loop has evolved from analog transmission on passive copper through digital carrier on copper to initial applications of fiber to customer premises. In planning its initial deployment of fiber to customer premises, AT&T analyzed a variety of optical devices and transmission techniques. It was decided to employ 1300-nm laser-based baseband duplex transmission employing fused fiber splitter devices. An optical interface lightguide unit was designed to house the optical components and protect them during assembly to a transceiver circuit board. This unit has proved compatible with a mass production factory environment. The optical transceivers have been deployed to sites throughout the US and have been performing reliably since the fall of 1988. The author discusses the choice of media, source, and wavelength; the lightguide unit; and the system characteristics