Terahertz Measurement Facility

    The Physics Department run a terahertz (THz) measurement and characterisation facility with capability to measure between 0.5 to 1.1 THz using a Rohde & Schwarz Vector Network Analyser (VNA) solution. The system uses a base VNA unit (ZVA24) and frequency extension (multiplier) heads which multiple a base frequency to THz frequencies between 500 and 1100 GHz (over two channels 500 to 750GHz and 750 to 1100 GHz). The system is capable of measuring precise spectral information to validate externally produced sources. Precise optical component testing is possible with our XYZ scanning facility allowing beam patterns to be measured in the near or farfields.

    We launch the THz signal from waveguide probes or specially designed horn antennae into free space and use an optical bench to introduce optical devices for test and characterisation. The THz signal from the frequency comb will be coupled to the VNA from free space using a photoconductive antenna and matching optics to the VNA for spectral analysis.

    Financial support for the measurement facility was provided to Maynooth University (Experimental Physics Department), by Science Foundation Ireland (SFI) under Grant Number 16/RI/3702
     

    Figure 1: Illustrated the THz measurement facility. The base VNA unit (in rack) transmits and receives a signal that is multiplied up to 1.1 THz and then radiated and received through the multiplier heads into optical components placed in the optical bench. Precise spectral information between 0.5 and 1.1 THz can be measured.
     
    Figure 2: A "4f" optical arrangement of mirrors to focus/collimate the free space THz signals produced. The optical behaviour of devices in the THz regime can be characterised precisely using this setup. Horn antenna/waveguide probes couple the radiation to free space from the multiplier heads. XYZ scanning not shown here.

    Staff: