Feasibility of "tunnel" mode locking in lasers

Attention is drawn to the feasiblity of "tunnel" mode locking in lasers with a dispersive medium in the resonator. An estimate is obtained of the tunnel length of a dispersive medium and of the width of the mode-locking band under typical conditions. These estimates were used to show that it should be possible to generate light pulses of duration down to 3×10^–14 sec.