On-chip THz Systems

A variety of novel on-chip terahertz systems have been developed with the aim of advancing current on-chip spectroscopic techniques. A novel methodology for the fabrication and positioning of isolated regions of photoconductive LT-GaAs thin film has been developed, allowing generation and detection of THz signals in-plane with a microstrip transmission line device. Devices with bandwidths in excess of 1.2 THz have been demonstrated. The introduction of novel, THz frequency passive resonator elements, in the form of quarter-wave band stop filters, into a transmission line device allowed measurements of the properties of overlaid dielectric films by monitoring of the resonant shift. Cascading multiple resonators along a single interconnect allowed simultaneous measurements to be performed at isolated frequencies at discrete locations on a single device. The first full characterisation of the resonant shift as a function of load thickness for a THz filter is performed, with measurements obtained in excellent agreement with subsequent free space studies, whilst requiring a 10' reduction in sample volume. Design modifications provided ultrahigh spectroscopic resolution in the terahertz range of