Fiber coupled terahertz time domain spectroscopy system based on InGaAs/InAlAs photoconductors with 100 dB dynamic range

We present an all fiber coupled terahertz (THz) time domain spectroscopy (THz-TDS) system operating at 1.5 μm wavelength with very high dynamic range. The broadband THz radiation is generated by a high mobility InGaAs/InAlAs heterostructure photoconductive emitter. For the detection a low temperature grown (LTG) Be-doped InGaAs/InAlAs heterostructure is employed. Both, detector and emitter, are packaged into fiber-coupled housings. The system reaches a dynamic range in excess of 100 dB and a spectral bandwidth of 6.5 THz.