“…The Kerr-lens mode-locked Ti-sapphire laser is the first demonstration of self-mode-locking. Noticeably, the self-mode-locking has recently been realized in various diode-pumped crystal lasers comprising Yb:KY(WO 4 ) 2 [13], Yb:KGd(WO 4 ) 2 [14], Yb:YVO 4 [15], Yb:Y 2 O 3 [16], Yb:YAG [17], Nd:YVO 4 [18,19], and Nd:GdVO 4 [20] crystals. Thanks to the self-mode-locked operation, the repetition rate can be up to several tens of GHz with a monolithic resonator [14].…”