A self-starting additive-pulse modelocked (APM) all-fiber ring cavity
laser operating in the negative group velocity regime is analyzed. The
advantages of using a ring cavity with an isolator are discussed. The
''figure eight'' and the Sagnac loop reflector fiber laser are invest
igated in a novel way, and one form of their operation is related to t
he master equation of APM. We point out that the ring laser has an adv
antage with respect to self-starting.