can be mode locked by a slow saturable absorber only, ie, the response time is much slower
than the width of the soliton. A Ti: sapphire laser mode locked by a low-temperature-grown
GaAs absorber with 10-ps recovery time generates pulses as short as 300 fs without the
need for Kerr-lens mode locking and critical cavity alignment. An extrapolation of this result
would predict that an≈ 100-fs recovery time of a semiconductor absorber could support …