The Laboratory for Optical Spectroscopy of Nanostructures (OSN) covers several spectroscopy techniques used for optical characterization of novel semiconducting materials and nanostructures. In general, they can operate in a spectral range of approx. 200 nm up to 6 µm in a standard dispersive mode, and up to 17 µm an behind, when using an FTIR-based approach. In all the cases in the temperature range of 2 - 400 K, and in the magnetic field up to 6 T or hydrostatic pressure up to 1.8 GPa. One of the main tools is modulation spectroscopy (photoreflectance (PR) and contactless electroreflectance (CER)), i.e. an absorption-like technique of enhanced sensitivity to optical transitions in low-dimensional systems. The other type of measurements are various emission-based methods from common photoluminescence, through its high spatial and spectral resolution mode – microphotoluminescence, photoluminescence excitation including a 2D mapping up to time resolved spectroscopy. The latter is based on double and synchronized fs/ps pulsed laser system (high power Ti:Sapphire oscillators plus an OPO, and second-third harmonics generation). The detection system for time resolved photoluminescence uses streak cameras (250 up to 1600 nm total detection range).
Additionally, the pump–probe time resolved reflectivity/transmittance is realized employing high resolution mechanical delay line. For mid and far infrared spectroscopy a setup based on a vacuum Fourier spectrometer with an additional custom designed external sample chamber for measurements with additional modulating beam (as in photoreflectance).