Introduction to ITST Terahertz User Facilities
Last two decades saw a rapid growth of applications in the THz spectral region thanks to the progress in methods of its generation and detection. Located between Infrared and millimeter waves THz light was previously accessible only in few research laboratories using expensive and complicated equipment. Closing the so called THz gap makes measurements in the region available to a wide group of users from fields as diverse as chemistry, biology, physics, materials science, public safety, etc. The mission of the ITST THz User Facilities is to promote this new technology by making it available to all interested research groups and industry professionals. Historically the first powerful source of THz radiation was built using free electron laser (FEL), where relativistic electrons are oscillating in the periodic magnetic field thus providing coupling between the electromagnetic wave and the electron beam. One of the first sources of this kind with a kilowatt-level THz radiation is still under operation in our facility and is available to users. One promising application where the high power of FEL is beneficial is a high frequency electron paramagnetic resonance (EPR). Probing systems with short relaxation times requires fast orientation of electron spins, which is possible in the high magnetic field and using a powerful source of electromagnetic radiation. This is where the combination of our FEL (240 GHz) and a 12.5 Tesla superconducting magnet comes in handy. Using a weaker Virginia Diode (VDI) source for high frequency cw EPR is also available. Another facility available to users is the vector network analyzer (VNA) in combination with Virginia Diodes (VNA/VDI) tunable sources of THz radiation. This piece of equipment gives a glimpse of what THz revolution is all about. Operating at room temperature with the spectral coverage region 70 GHz – 700 GHz, this self-contained desktop instrument gives the user unprecedented flexibility and new possibilities due to the high dynamic range (up to 140 dB) and a capability to detect both amplitude and phase of the electromagnetic wave. These are not all possibilities available with our equipment. If you have some other applications in mind please contact us and we will use our expertise to help you to realize them in our THz facilities.
240 GHz wave in real scale