We pump a saturable Bragg reflector (SBR)‐mode‐locked Cr:LiSAF laser with a 0.5 W diffraction‐limited 670 nm laser diode and obtain average CW mode‐locked power of 100 mW of 70 fs pulses at &lgr;=868 nm. The low loss of the SBR‐mode‐locking technique combined with a nearly diffraction limited pumping results in the highest optical conversion efficiency obtained with this type of laser to date. We discuss overall electrical efficiency of femtosecond lasers. ©1996 American Institute of Physics.