Practical limitations on optical amplifier performance

Practical issues are considered to determine if significant improvements in the sensitivity, of 1.55-μm optical receivers can be realized through the use of semiconductor laser preamplifiers. It is found that practical problems related to realizable values of population inversion parameter, input coupling losses, external optical filter requirements, polarization effects, and source laser stability make it unlikely that optical preamplifiers can approach their optimum performance at data rates below several Gbit/s. The most promising application of optical preamplifiers will therefore be to increase the sensitivity of receivers in future fiber optic communication systems operating at multigigabit data rates.