Compact THz Spectrometers offered by Microtech Instruments， Inc. enable transmission measurements in thespectral range of 100 GHz to 1.5 THz. These systems are based on millimeter wave Backward Wave Oscillators (BWO's) combined with frequency multipliers and broadband Pyroelectric Detectors.
Key Features Include:
? Spectral Range: 100 GHz - 1.5 THz
? Spectral Resolution: 1 - 10 MHz
? Dynamic Range: 10^4
Compact THz Spectrometer:
THz spectrometers offered by Microtech Instruments enable high-resolution spectroscopic measurements in the spectral range from 180 GHz to 1.42 THz. These systems employ frequency tunable Backward Wave Oscillators (BWOs) as sources of THz radiation and Golay Cells as detectors.
Key features include:
? Spectral range: 30 GHz - 1.42 THz
? Spectral resolution: 1- 10 MHz
? Dynamic Range: 10^5
| Model | Operating Spectral Range |
| TScan-260 | 180 - 260 GHz |
| TScan-370 | 180 - 370 GHz |
| TScan-1100 | 180 - 1100 GHz |
| TScan-1250 | 180 - 1250 GHz |
| TScan-1420 | 180 - 1420 GHz |
THz Transmission Spectrometer:
Transmission measurement is the best method for characterization of highly transparent materials. In particular， transmission spectra of plane parallel plates exhibit a periodic transmission pattern caused by interference (Fabry-Perot etalon fringes). Real and imaginary parts of the dielectric constant can be determined from these measurements， as the period and amplitude of the etalon fringes depend on the material refractive index and absorption， respectively.
Characterization of semi-transparent materials requires a THz Mach-Zehnder interferometer (shown below)， since no etalon fringes can be observed in the transmission spectra of such materials. The Mach-Zehnder setup enables measurements of a phase shift induced by the sample as a function of frequency. Combining this data with transmission spectrum， real and imaginary parts of the dielectric constant can be calculated.
THz Mach-Zehnder Spectrometer:
Characterization of semi-transparent materials requires a THz Mach-Zehnder inferometer (shown below)， since no etalon fringes can be observed in the transmission spectra of such materials. The Mach-Zehnder setup enables measurements of a phase shift induced by the sample as a function of frequency. Combining this data with transmission spectrum， real and imaginary parts of the dielectric constant can be calculated.
Highly absorptive materials can only be characterized in a reflection geometry， illustrated below.
THz Reflection Spectrometer:
Opaque materials characterization requires the reflection spectrometer (shown above). Because the transmitted signal is too small for characterization， a system using 6-axis control is employed to measure the reflected signal. As with the transmission and phase spectrometers the index of refraction， extinction coefficient and the real and imaginary parts of the dielectic function can be quickly calculated from the software's theoretical fitting capacity.
The transmission， Mach-Zehnder and reflection spectrometers are supported by TScan software， enabling automated data acquisition and analysis. One spectral scan takes 1 - 5 minutes for each of the BWOs employed in the system.
