Filters

2018 - 201912020 - 20211

More filters

2022 - 20232
Reset filters

Settings

Subject: Sapphire × WGL Institute: MBI ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    8 fs laser pulses from a compact gas-filled multi-pass cell
    (Washington, DC : Soc., 2021) Rueda, P.; Videla, F.; Witting, T.; Torchia, G.A.; Furch, F.J.
    Compression of 42 fs, 0.29 mJ pulses from a Ti:Sapphire amplifier down to 8 fs (approximately 3 optical cycles) is demonstrated by means of spectral broadening in a compact multi-pass cell filled with argon. The efficiency of the nonlinear pulse compression is limited to 45 % mostly by losses in the mirrors of the cell. The experimental results are supported by 3-dimensional numerical simulations of the nonlinear pulse propagation in the cell that allow us to study spatio-spectral properties of the pulses after spectral broadening.
  • Thumbnail Image
    Item
    Vibrational sum-frequency generation spectroscopy of lipid bilayers at repetition rates up to 100 kHz
    (Melville, NY : American Institute of Physics, 2018) Yesudas, Freeda; Mero, Mark; Kneipp, Janina; Heiner, Zsuzsanna
    Broadband vibrational sum-frequency generation (BB-VSFG) spectroscopy has become a well-established surface analytical tool capable of identifying the orientation and structure of molecular layers. A straightforward way to boost the sensitivity of the technique could be to increase the laser repetition rate beyond that of standard BB-VSFG spectrometers, which rely on Ti:sapphire lasers operating at repetition rates of 1-5 kHz. Nevertheless, possible thermally induced artifacts in the vibrational spectra due to higher laser average powers are unexplored. Here, we discuss laser power induced temperature accumulation effects that distort the BB-VSFG spectra of 1,2-diacyl-sn-glycero-3-phosphocholine at an interface between two transparent phases at repetition rates of 5, 10, 50, and 100 kHz at constant pulse energy. No heat-induced distortions were found in the spectra, suggesting that the increase in the laser repetition rate provides a feasible route to an improved signal-to-noise ratio or shorter data acquisition times in BB-VSFG spectroscopy for thin films on transparent substrates. The results have implications for future BB-VSFG spectrometers pushing the detection limit for molecular layers with low surface coverage.