High-speed coherent CW terahertz spectrometer

In-fibre wavelength selective modulation of the optical phase enables the electro-optic control of the terahertz phase in continuous-wave photomixing terahertz systems without any free-space optics. Using a fully fibre-coupled terahertz setup, a coherent scan of a frequency range of 1.5 THz with 100 MHz resolution in less than 24 s is demonstrated. This sample rate of 1.6 ms/sample is more than 20 times faster than any previous broadband scans reported.