- Lannion ENSSAT
Dans le cadre des conférences du cursus ingénieur Optronique de l'Enssat, le laboratoire Foton vous invite au séminaire public
« The Limits of Optical Fibers to Transmit Information »
Dr. René-Jean Essiambre (Bell Labs - USA)
The maximum rate of transmission of information over single-mode optical fibers has increased by four orders of magnitude over the last three decades. A question naturally arises : is there a fundamental limit to the maximum achievable transmission rate, or capacity, of single-mode fibers ?
In the first part of this presentation, I will discuss studies on the capacity limit imposed on single-mode fibers by the Kerr fiber nonlinearity and Shannon`s information theory. I will show that the record capacities achieved experimentally are currently within a factor 2 from the maximum capacity predictions and appear to be saturating near this level. I will discuss the technologies needed to closely approach the nonlinear fiber capacity limit and the variation in the capacity of various single-mode fiber types.
Assuming that we cannot exceed the predicted capacity limit of single-mode fibers, what are the alternatives to increase fiber capacity ? Can multimode, few-mode and multicore fibers be an alternative to multiple single-mode fibers ? In the second part of the presentation, I will discuss how SDM over a single fiber strand can be used for increasing capacity using technologies such as MIMO DSP and spatial mode couplers. I will also present evidence of nonlinear limitations in transmission over SDM fibers with the experimental observation of inter-modal nonlinear effects in a 5-km long few-mode fiber.