With a homemade semiconductor saturable absorber mirror (SESAM), different cavities have been designed to achieve mode-locking. Linear cavity continuous-wave mode-locking (CWML) lasers of single output beam with average power of 5 W, double output beams with average power of 5 W and adjustable output transmission have been presented. Bi-directional operation ring cavity passively continuous wave (CW) mode-locked laser end-pumped by a fiber coupled laser diode has been constructed. By placing the semiconductor absorber mirror in a special location, a new mode-locking technique for multiplying the pulse repetition rate of a picosecond passively mode-locking laser was successfully demonstrated. And 4 W mode-locking output of LD end-pumped Nd∶YVO4 laser was achieved by using a nonlinear mirror, which is constituted by a combination of a KTP frequency-doubling crystal and a dichroic mirror with high reflectivity for the second harmonic and partial transmission for the fundamental.