DESIGN AND CHARACTERIZATION OF DISPERSION COMPENSATING FIBER BASED ON THE LP01 MODE

The practical implementation of erbium-doped fiber amplifiers with gain at 1.55 mum allows long unrepeatered transmission distances. However, in order to realize high data rates over these distances with already installed standard single mode fiber, techniques must be found to overcome the pulse spreading due to the positive chromatic dispersion of the transmission fiber in this window. We review a compensation technique based on propagating the signals through a specially designed fiber with large negative dispersion for the LP01 mode, thereby ending up with zero net pulse spreading. The basis of the concept are discussed and a key figure of merit for dispersion compensating devices is defined. The design and optimization of dispersion compensating (DC) fiber is described with special attention to practical concerns including packaging and manufacturability. We describe experimental fabrication results of DC fiber, results of using the fiber to make compact dispersion compensating modules, and the outcome of recent systems experiments incorporating the fiber.