Applications of Tekhnoscan's narrow-line lasers in nano-science and nano-technologies Characterisation of semiconductor nano-particles possessing quantum-dimension properties (quantum wells, dots, and threads) with respect to their optical parameters is now one of important problems within the industry of new materials and nano-systems. These quantum nano-structures have quasi-atomic energy spectra, which depend on their size and composition. For instance, typical absorption line widths in isolated quantum dots amount to 0.05-0.1 meV (0.4-0.8 cm-1), corresponding to 12.1-24.2 GHz. In order to study and identify quantum structures with the use of spectral methods it is most desirable to use lasers with tuneable output wavelength and the line width at least by an order of magnitude narrower than typical absorption lines in these structures. Informative absorption spectra of nano-structures may be located in UV, visible, as well as in IR ranges. Because of this, in spectral methods of contemporary nano-technologies the most required laser sources are those providing ultra-wide detuning range (from UV to IR) and having output line width around 1-2 GHz. Parameters and generation modes of computer-controlled tuneable laser system "T&D-scan" developed and manufactured by Tekhnoscan are the best fit for laser-optical characterisation of quantum dot properties. The full set of T&D-scan options allows it to cover a spectral range from 275 to 1100 nm while having the output line width around 0.5-1 GHz. The spectrometer includes a built-in high-precision radiation wavelength meter and a system of automatic control over the spectrally selective laser elements, thus providing the possibility to automatically set the output radiation wavelength to the absolute precision of 1 GHz (0.004 meV, or 0.03 cm-1) and to perform continuous scanning of the output radiation line in a specified spectral range. Laser system "T&D-scan" also has functions and modules for multi-channel data acquisition and additional channels for computer control, bringing it to the level of fully functional laser-optical workstation for a scientist or nano-technologist. << Laser Applications in nano-science and nano-technologies.