Time and Change. Researchers in the Kohler Group acquire expertise in a wide variety of ultrafast spectroscopic techniques. Systems of interest are studied using broadband transient absorption, fluorescence upconversion, time-resolved infrared (TRIR) and 2D-IR spectrometers. In the pump-probe measurements that are central to our work, a femtosecond pump pulse less than 100 fs (10-13 s) in duration ‘instantly’ prepares transient excited states, which are then probed as a function of time using electronic and vibrational spectroscopy. In analogy to microscopy, which provides access to miniscule spatial dimensions, femtosecond laser spectroscopy reveals the temporal evolution of the microscopic world.

Multi-user instrumentation available through the many, shared facilities at OSU augments the spectroscopic tools in our laboratories. We make frequent use of and students receive training in how to characterize nanomaterials using X-ray diffraction (XRD), high resolution transmission electron microscopy (TEM), dynamic light scattering, atomic force microscopy (AFM), and analytical ultracentrifugation (AUC).

Laser Systems

The South T:

  • Astrella Integrated Ti:S Amplifier
  • Topas Prime (UV-VIS extension: 240 nm)
  • Topas Prime (DUV-UV-VIS extension: 190 nm)
  • Topas Prime (nDFG extension)
  • PhaseTech 2DQUICK IR(with Transient Module)

The North T:

  • Libra Integrated Ti:S Amplifier
  •  OPerA Solo OPA X2
  • Topas C (with nDFG)
  • Coherent Infinity Nd-Yag

Steady State Equipment

  • Cary 5000 UV-Vis-NIR Spectrometer
    • Diffuse Reflectance Accessory
  • Horiba Modular Flourimeter with NIR capability
    • Lock-in Amplifier
  • Jasco J-815 CD Spectrometer
  • Jasco FT/IR-4200
    • ATR attachement
  • PerkinElmer Lambda 25 Uv-Vis Spectrometer