Cross-gain modulation and frequency conversion crosstalk effects in 1550-nm gain-clamped semiconductor optical amplifiers

We present data on the crosstalk characteristics of a gain-clamped semiconductor optical amplifier with input data on separate wavelength channels, spaced by /spl sim/1 nm. As predicted for a gain-clamped device, we observe very little crosstalk due to cross-gain modulation. Frequency conversion, most likely due to parametric amplification, occurs at relatively low thresholds (/spl sim/-7 dBm total input), but is limited entirely to the continuous-wave component of the optical input and does not appear to contribute to the RF crosstalk. Our data also reveal that input power levels have an observable impart on the signal-to-noise ratio at low injection levels.