The intermodulation distortion (IMD) characteristics of a subcarrier multiplexed signal in semiconductor laser amplifiers have been calculated. The minimum value of the carrier to the second-order IMD with detuning decreases 3 dB for the amplifier under consideration when the facet reflectivity changes from 10(-4) to 10(-3). In the case of third-order IMD the minimum value of the carrier to IMD ratio with detuning decreases 10 dB for the same change of reflectivity.