A novel device is designed to replace the commercial 1053 nm femtosecond mode-locked laser oscillator. In this device, optical parametric chirped pulse amplification (OPCPA) is applied to realize energy amplification and wavelength conversion, and 3160 nm mid-infrared laser pulse is produced as the fundamental wave. Then a high signal to noise ratio (SNR) 1053 nm output pulse is got by the third harmonic generation (THG) process. The application of this device is expected to enhance the SNR of petawatt front-end and improve the SNR of the whole petawatt system at the same time.