Fiber loop optical buffer

Fiber loop optical buffers enable data storage for discrete time intervals and therefore appear suitable for applications in optical asynchronous transfer mode (OATM)-based networks where data are transmitted in cells of fixed length. In this paper, the feasibility and the limitations of optical data storage in a fiber loop optical buffer are studied theoretically and experimentally, A model of a fiber loop buffer, incorporating semiconductor laser amplifiers (SLA) as switching gates, is described. The two major interfering quantities are cross talk and amplified spontaneous emission of the SLA gates. To limit the impact of cross talk on the signal quality, an on/off ratio of the SLA gates of at least 30 dB is required. The paper describes the optimum operation conditions, which enable data storage for more than 100 circulations even for data rates in the range from 10 to 160 Gb/s.