power penalty
5.Single ridge waveguide EML incorporating InP window and anti-reflection optical film coating is fabricated by selective area growth. No power penalty is observed at a bit-error-ratio of 10 -12 after standard single mode fiber transmission of 280km long when the EML is modulated with 25Gb/s NRZ 2 23-1 PRBS data.
6.In this parer the influence of cross-phase modulation(XPM) on the performance of dense wavelength division multiplexed (DWDM)optical fiber transmission systems is studied. A system model which describes ar- bitrary modulated signals transmitting through XPM channels established and, is the XPM-induced system optical power penalty under different system conditions is calcalated.

