RESUMEN
We investigate the influence of Beryllium (Be) doping on the performance of photoconductive THz detectors based on molecular beam epitaxy (MBE) of low temperature (LT) grown In(0.53)Ga(0.47)As/In(0.52)Al(0.48)As multilayer heterostructures (MLHS). We show how the optical excitation power affects carrier lifetime, detector signal, dynamic range and bandwidth in THz time domain spectroscopy (TDS) in dependence on Be-doping concentration. For optimal doping we measured a THz bandwidth in excess of 6 THz and a dynamic range of up to 90 dB.
RESUMEN
A modified photoconductive receiver significantly improves the performance of photomixing-based continuous wave (cw) THz systems driven at the optical telecommunication wavelength of 1.5 µm. The achieved signal-to-noise ratio of 105 dB at 100 GHz and 70 dB at 1 THz, both for an integration time of 200 ms, are to our knowledge the highest numbers reported in literature for any optoelectronic cw THz system, including classical setups operating at 800 nm. The developed receiver allows for combining low cost and high performance in one system for the first time to our knowledge.