  Photoluminescence (PL) has become a common tool to characterize various
properties of single-walled carbon nanotube (SWCNT) chirality distribution and
the level of tube individualization in SWCNT samples. Most PL studies employ
conventional lamp light sources whose spectral distribution is filtered with a
monochromator but this results in a still impure spectrum with a low spectral
intensity. Tunable dye lasers offer a tunable light source which cover the
desired excitation wavelength range with a high spectral intensity, but their
operation is often cumbersome. Here, we present the design and properties of an
improved dye-laser system which is based on a Q-switch pump laser. The high
peak power of the pump provides an essentially threshold-free lasing of the dye
laser which substantially improves the operability. It allows operation with
laser dyes such as Rhodamin 110 and Pyridin 1, which are otherwise on the
border of operation of our laser. Our system allows to cover the 540-730 nm
wavelength range with 4 dyes. In addition, the dye laser output pulses closely
follow the properties of the pump this it directly provides a time resolved and
tunable laser source. We demonstrate the performance of the system by measuring
the photoluminescence map of a HiPco single-walled carbon nanotubes sample.
