A lidar system includes a laser diode to provide a frequency modulated continuous wave (FMCW) signal, and a current source to provide a drive signal that modulates the laser diode. The current source is controlled to pre-distort the drive signal to provide a linear FMCW signal. The lidar system also includes a splitter to split the FMCW signal into an output signal and a local oscillator (LO) signal, a transmit coupler to transmit the output signal, a receive coupler to obtain a received signal based on reflection of the output signal by a target, and a combiner to combine the received signal with the LO signal into first and second combined signals. A first and second photodetector respectively receive the first and second combined signals and output first and second electrical signals from which a beat signal that indicates the pre-distortion needed for the drive signal is obtained.