A new type of diffusion-bonded Nd:YVO 4 /Nd:GdVO 4 heterocomposite crystal is originally designed and applied to diode-end-pumped laser for achieving an efficient dual-comb picosecond operation with selfmode locking for the first time. As high as 1.1 W of the total average output power at 1063.18 and 1064.37 nm is generated under an incident pump power of 5.1 W. The corresponding mode-locked pulse width is 42 ps at a pulse repetition rate of 3.82 GHz. Through the optical beating between two carrier frequencies of each spectral component, a train of ultrashort pulses with sub-terahertz repetition rate is further generated with the effective duration of down to 1.6 ps.