Over the past three decades a variety of detection techniques have been used to probe the ultrafast dynamics of complex molecular and semiconductor systems. These techniques include absorption, fluorescence, multiphoton ionisation, photoelectron detection, fourwave mixing, stimulated Raman and photon echo. Very recently there has been much interest in developing multidimensional femtosecond laser techniques similar to those successfully used in NMR to study ultrafast dynamical processes. These include non-linear multiple-pulse coherent techniques which probe correlations between the electric fields generated in the phasematching directions by the different laser pulses and allow detailed spectroscopic information to be obtained in the presence of inhomogeneous broadening.
In the image shown above, three laser pulses generate third (or higher) order polarization and result in spatially distributed electric fields generated in various phase-matching directions. From this data, detailed spectroscopic information can be extracted.
Spreading the information over more than one dimension, for example, by using several pulses with independently controllable time delays, helps to unravel and extract the complex dynamical and spectroscopic information, such as relaxation rates of the level populations, dephasing rates or inhomogeneous broadening of the optical transition. Suitable selection of the wavelengths and polarizations of the laser pulses allows different sets of energy levels to be selected and the dynamics in the ground and excited states to be separated and investigated. The multidimensional non-linear spectroscopic techniques supported by MMULS open up new opportunities to explore the dynamics of complex systems that are not possible or very limited with traditional time-resolved spectroscopic techniques with single pump laser pulses.
Key Features:
- Simultaneous whole spectrum sampling in 4 channels • Dual delay lines, +/-1 ns delay, 1 fs resolution
- For use with MHz oscillators & kHz regenerative lasers
- Fully integrated, working solution with proven software
- Multifunctional platform for ultrafast laser spectroscopy
- Multiple or single pump probe
- White light continuum probe option
- Spectrally resolved photon echoes
- Four-wave mixing
- Laser induced transient grating
- Anisotropy spectroscopy
- In situ FROG measurements for pulse characterization using optical Kerr effect
Download MMULS Brochure here.
Download technical note "Innovative Spectrometers and Detectors for Multiple Beam Ultrafast Laser Spectroscopy" here.
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