Laboratory of Far-InfraRed Magnetospectroscopy (FIRM) is equipped with optically pumped THz gas laser, cryomagnetic cryostat and bolometer. Unique experimental setup enable us to measure optical properties of materials in the far-infrared region at low temperatures down to 3 K and in magnetic fields up to 11 tesla.
Terahertz gas laser
FIRL100 terahertz gas laser provides a series of linearly polarized lines with frequencies in the range from 0.3 to 7.5 THz and output power from 1 to 100 mW. Gases flowing through the glass tube in the FIR part of the system serve as an active medium for the generation of THz radiation. The inversion population of vibration-rotational energy levels of the molecules is achieved by optical pumping using a tunable CO2 laser. Part of the beam is deflected on a pyroelectric detector, which is used for monitoring of the laser power output. Linear polarization of any laser line can be changed for an elliptical or circular polarization by inserting a special optical device that we have designed for this purpose. The beam is concentrated by the parabolic mirror to the sample placed in an optical cryostat and after passing through the sample is detected on the bolometer.
Spectromag SM4000 cryomagnetic system allows - for any given laser line - detailed monitoring of dependence of optical transmission properties of the sample on temperature and magnetic field. Simultaneously with the measurement of optical properties the electrical resistance can be monitored using four point probe measurement with contacts arranged at the corners of the sample.