Abstract

An antiresonant (AR) ring has been proposed by Siegman¹ to obtain standing wave saturation in a linear mode-locked dye laser. This laser configuration is equivalent to that of a mode-locked ring laser if the saturable absorber is located at equal optical distance from the beam splitter (Fig. 1). Two technical problems seem to make this configuration impractical: a) The requirement of tight focusing in the absorber^2,3 implies a large beam size through the beam splitter, hence a large angle of the AR triangle, and a large astigmatism impeding the tight focusing. b) It seems impractical to fulfill the "colliding pulse" condition for femtosecond pulses, since it requires to maintain equality of the two arms of the AR ring with an accuracy of 10 microns.

© 1986 Optical Society of America