The mode-locked laser with improved pulse power output can be realized by combining an optical oscillator with a flared CW or modulated gain amplifier. An optical filter or isolator may be disposed between the oscillator and amplifier to avoid feedback of spontaneous noise. A two-segment laser is devised by providing a flared gain section between a modulated gain section and an absorber section within the integrated semiconductor laser. The flared section may taper from a larger modulated gain section to a smaller cross section absorber section or vice versa. Various combinations of absorber sections coupled to modulated gain sections by CW gain or passive flared gain sections may be combined with various arrangements of reflectors and tapered CW gain amplifiers are cascades of such amplifiers and modulated gain pairs. A saturable absorber may be used in a two-segment laser in which the absorber is bleachable and has a characteristic temperature which is increased during short time periods so that a passive gain is realized by the return pulse traveling through the saturable absorber provided that the returning pulse is timed to coincide with the temporal gain realized in the absorber.