Abstract

In high-speed optical regenerative repeater systems, the use of EDFAs enables large bandwidth baseband amplification in the optical frequency domain in contrast to conventional amplifiers which operate in the electrical frequency domain.⁽¹⁾ On the other hand, existing timing clock extraction schemes use only in electrical domain; electrical filters with high quality factors (Q) such as dielectric resonator and SAW filter are commonly employed. However, when the operating bit rate is beyond 10 Gbit/s, it becomes more difficult to realize stable operation of tuning and limiting electrical amplifier and suppress spurious modes in the electrical resonator. To solve these problems, passive optical tank circuits such as ring type or Fabry-Perot type resonators have proposed(2). In these optical tanks, however, it is impossible to control the center frequency of each pass band and the free spectral range (FSR) independently.

© 1993 Optical Society of America