a Temporal waveform of the generated LCMW with a positive chirp rate by beating the frequency-chirped optical pulse with an optical carrier from an LD at a high-speed PD. The zoom-in views of the waveform are shown in (b and c). The blue dots in (c) are the originally recorded data and the red lines are the fitted waveforms. d Spectrogram of the waveform shown in (a). e Compressed pulse by autocorrelation.