Temporal self-referencing technique for the diagnostics of nanosecond laser pulse

•The manuscript proposed a linear self-referencing technique to diagnostic the temporal phase distribution and the precise spectra of nanosecond laser pulses.•Data acquisition of this proposed method is realized with a normal acousto-optic frequency shifter and an oscilloscope.•The proposed method is computationally efficient and operationally simple, providing a higher speed and accuracy for a wider range of applications.