Terahertz Spectroscopy

for Materials Characterization

Examples:

(Left) Photograph of an epitaxially grown GaAs layer. The right-low quarter of the layer has been removed for referencing. (Right) Carrier life-time map obtained by photo-excitation the GaAs layer at 800 nm and measurements of the THz near-field transmission. The carrier life-time map is taken in area of 1 mm x 1 mm at the center of the sample.

Terahertz Time-Domain Near-Field Microscopy

High-spatial resolution THz near-field microscope. The THz microscope allows to measure the THz radiation transmitted through a sample at the surface with a scanning near-field probe. By using near-field detection, this setup overcomes the main limitation of THz spectroscopy, i.e., the spatial resolution. The combination of THz near-field microscopy with optical pump provides a unique instrument for the investigation of the transient photo-conductivity and the carrier life-time of photo-excited semiconductors.

This technology has been developed with financial support of the European Research Council through the ERC- Proof of Concept grant (MicroMap, grant number 665619).

Features

THz bandwidth: 0.07 – 1 THz
Scanning area: 1 cm2
Spatial resolution: appr. 25 μm
Excitation wavelength: 400 – 1000 nm
Time resolution: 100 fs
Possibility of detecting electric field components along x, y and z directions

More information about our THz nearfield microscope can be found below.