EPSRC THz facility

Access NPL’s world-leading terahertz facilities

This facility will also allow us to push the boundaries on many metrology and testing concepts for next generation wireless communications specially at sub-THz and beyond.

Dr Akram Alomainy - QMUL

NPL is home to the EPSRC THz facility, serving the UK academic community. Through EPSRC funding, you can apply to use NPL’s THz facilities and services which include:

• Time-domain spectroscopy 
• Frequency-domain spectroscopy
• Device characterisation 
• THz communications 

The equipment and resources of the THz facility are listed below and can be accessed through the EPSRC applications process.

Please contact us to discuss proposed work or if you have any questions.

Contact us

Time-domain spectroscopy

Transmission time-domain spectroscopy

• Equipment: TeraFlash Pro (Toptica)  

• Measurement: Frequency range 0.1 – 6 THz, Frequency resolution 1 GHz 

• Measurement with either collimated or focused beam 

Time-domain spectroscopy imaging extension 

• Equipment: operates with TeraFlash Pro (Toptica) 
• Measurement: Transmission or reflection 
• Measurement area: 15 x 15 cm 

Reflection time-domain spectroscopy 

• Equipment: Tera K15 (Menlo) 
• Measurement: Frequency range 0.1 – 5 THz, Frequency resolution 5 GHz

Frequency-domain spectroscopy

Transmission frequency-domain spectroscopy 

• Equipment: TeraScan (Toptica) 
• Measurement: Frequency range 0.05 – 2 THz, Frequency resolution 50 MHz 
• Measurement with either collimated or focused beam 

Broadband spectral measurements – lamellar interferometer 

• Measurement: Frequency range 0.05 – 10 THz, Frequency resolution 1 GHz 
• Emitter broadband spectrum (requires calibrated detector) 
• Detector spectral responsivity (requires calibrated emitter) 

Device characterisation 

Emitter beam profile 

• Operates with pyroelectric detector and Golay cell 
• Measurement: Frequency range 0.1 – 10 THz 
• Measures angular beam profile 
• Angular resolution: 1° 

THz power 

• Equipment: calibrated THz power detectors - Pyroelectric detector (SLT) and Golay cell (Tydex) 
• Measurement: Frequency range 0.1 – 10 THz 

Ti-sapphire mode-locked laser 

• Equipment: Femtosource mode-locked Ti-sapphire laser and
  coherent Verdi pump laser 
• 20 fs pulse length 
• Low noise, high stability  

Vector network analyser (VNA) 

• Equipment: Keysight PNA-X VNA  
• Configured to measure:  
• metallic waveguides 
  • on-wafer substrates 
  • materials characterisation 
  • + VDI power meter 

• Waveguide measurement (S-parameters, power level) 
• On-wafer probing (S-parameters, power level) 
• Material measurement using material characterisation kit (MCK) 
• A separate power meter can measure power in all the above bands 

Metallic waveguide measurements 

• Instrumentation: VDI extender heads 
• Primary standards: NPL-designed waveguide lines (¾ wavelength) 
• Calibration: NPL-invented ¾-wave Thru-Reflect-Line (TRL) technique 
• Uncertainty: evaluated using Guide to expression of Uncertainty in Measurement (GUM) 
• Traceability: to SI via International Bureau of Weights & Measures (BIPM) 

On-wafer measurements 

• Equipment: MPI THz manual probe station with state-of-the-art system enabling accurate on-wafer probing to 750 GHz  
• Thermal chuck allowing measurement over temperature from 25 °C to 150 °C 
• Different testing boundaries: metal, absorbing materials, ceramic 
• G-S-G probes (with integrated bias-T) and calibration substrates available 

Materials measurement using material characterisation kits (MCKs) 

• MCK is effectively a guided free-space technique 
• Sample clamped between 2 corrugated horn antennas  
• Horn operates in HE11 mode (ultra-low loss), launching 98 % pure Gaussian beam 
• Compared to conventional free-space technique, MCKs are more compact and have less stringent requirements on alignment  
• Good agreement achieved between MCK and TDS 

Power measurement using VDI power meter 

• Equipment: VDI PM5 – a popular commercial power meter for applications from 75 GHz to > 3 THz 
• primary power standards up to 170 GHz are available, providing traceability to SI, through waveguide-based micro-calorimeters 

THz wireless communications 

THz communications testbed   

Equipment includes: 

• PIN and UTC photodiodes for THz transmitters 
• High-bandwidth optical IQ modulator with linear RF amplifiers 
• Arbitrary waveform generator 
• Subharmonic mixer (SHM) and Schottky-barrier diode (SBD) for THz receivers 
• Real-time oscilloscopes 
• Digital Signal Processing (DSP) expertise for higher-order modulation formats 

Please contact us to discuss proposed work or if you have any questions.  

Contact us

NPL’s EPSRC THz facility provides access to state-of-the-art THz facilities as well as collaborative THz research opportunities with outstanding scientists at NPL. I believe the EPSRC THz facility at NPL will play a key role for the UK to lead the advancement of THz sciences by collaborating with other institutions domestically and internationally using its enormous THz research capacity.

Dr SaeJune Park - QMUL