Fourier transform second harmonic generation for high-resolution nonlinear spectroscopy

In this communication we demonstrate a new characterization technique combining Fourier transform (FT) spectroscopy and second harmonic generation (SHG) that enables high spectral resolution with broadband femtosecond laser pulses. The strong and narrow exciton resonances of the wide band gap semiconductor ZnO were chosen for demonstrating the capabilities of the method. FT-SHG offers high reproducibility and high spectral resolution within the bandwidth of the input pulse. •High spectral resolution nonlinear spectroscopy using femtosecond laser pulses.•FT-SHG offers high spectral resolution independent of input pulse characteristics.•High spectral reproducibility due to the built-in calibration of the spectral axis.•The FT-SHG technique is enhanced if spectrally broad laser pulses are utilized.