Abstract

Semiconductor laser amplifiers have been studied extensively In the last few years because of their potential for optical fiber communication system application. When used as optical repeaters, they will work as simple and flexible repeaters for the expansion of wavelength multiplexed channels and the change of the data rate. They can serve to expand the regenerative repeater spacing in IM direct detection systems^1,2 and also in coherent detection systems.^3,4 Preamplifiers to improve receiver sensitivity³ and booster amplifiers to compensate for insertion loss and power splitting loss in optical circuits are also promising applications. We will present here a simple definition of the noise figure for semiconductor laser amplifiers, which is useful in evaluation of the SNRs in these systems.

© 1983 Optical Society of America