Terahertz cross-correlation spectroscopy driven by incoherent light from a superluminescent diode

We present a novel terahertz spectroscopy principle by using incoherent light from a superluminescent diode for terahertz cross-correlation spectroscopy. The combless nature of this light source leads to a truly continuous terahertz spectrum. We demonstrate the possibility to influence the terahertz spectral bandwidth of the system by changing the bandwidth of different bandpass filters in the system. Depending on the employed bandpass filter we achieve peak dynamic ranges of 60 dB or a terahertz spectral width of about 1.7 THz. The applicability of the measurement system to spectroscopic terahertz measurement tasks is demonstrated. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement