TY - JOUR AU - Lang, Bernhard AU - Mosquera-Vazquez, Sandra AU - Lovy, Dominique AU - Sherin, Peter AU - Markovic, Vesna AU - Vauthey, Eric TI - Broadband ultraviolet-visible transient absorption spectroscopy in the nanosecond to microsecond time domain with sub-nanosecond time resolution PY - 2013 JF - Review of Scientific Instruments JA - Rev. Sci. Instr. SN - 0034-6748 VL - 84 IS - 7 SP - 73107 L1 - http://scitation.aip.org/getpdf/servlet/GetPDFServlet?filetype=pdf&id=RSINAK000084000007073107000001&idtype=cvips&doi=10.1063/1.4812705&prog=normal L2 - http://rsi.aip.org/resource/1/rsinak/v84/i7/p073107_s1?view=fulltext L3 - http://link.aip.org/link/RSINAK/v84/i7/p073107/s1&Agg=doi L4 - http://www.unige.ch/sciences/chifi/publis/pics/double/ref01366.png M3 - 10.1063/1.4812705 UR - http://dx.doi.org/10.1063/1.4812705 KW - delays KW - high-speed optical techniques KW - measurement by laser beam KW - neodymium KW - optical sensors KW - photodetectors KW - photoexcitation KW - photolysis KW - probes KW - Q-switching KW - solid lasers KW - time-domain analysis KW - timing jitter KW - ultraviolet spectroscopy KW - visible spectroscopy N2 - A combination of sub-nanosecond photoexcitation and femtosecond supercontinuum probing is used to extend femtosecond transient absorption spectroscopy into the nanosecond to microsecond time domain. Employing a passively Q-switched frequency tripled Nd:YAG laser and determining the jitter of the time delay between excitation and probe pulses with a high resolution time delay counter on a single-shot basis leads to a time resolution of 350 ps in picosecond excitation mode. The time overlap of almost an order of magnitude between fs and sub-ns excitation mode permits to extend ultrafast transient absorption (TA) experiments seamlessly into time ranges traditionally covered by laser flash photolysis. The broadband detection scheme eases the identification of intermediate reaction products which may remain undetected in single-wavelength detection flash photolysis arrangements. Single-shot referencing of the supercontinuum probe with two identical spectrometer/CCD arrangements yields an excellent signal-to-noise ratio for the so far investigated chromophores in short to moderate accumulation times. ID - 1366 ER -