Ultrafast dynamics of chemical reactions, excited state dynamics
Conformation dynamics and kinetics in fluorescent molecules
Quantum dots characterization
Bioorganic photosynthetic system analysis
Dynamics in fluorescent proteins and DNA constituents
Carrier dynamics in nanocrystals and nanoparticles
Proton transfer
Dye/label photophysics
Newport’s Time-Resolved Fluorescence Spectrometer (TRFLS) offers versatile functionality for researchers gathering fluorescence kinetic traces. The standard fluorescence upconversion platform can be coupled with an ultrafast oscillator, amplifier, SHG/THG, OPA/OPO, while the optional time-correlated single photon counting setup can be added to systems pumped by fs oscillators.
In fluorescent upconversion, the fluorescent sample is pumped by a femtosecond pulse and the fluorescence is upconverted using an optically gated pulse to generate sum frequency radiation. The upconverted light is then spectrally resolved via monochromator or spectrograph using a PMT. The software automatically controls the upconversion crystal’s phase matching angle and monochromator grating angle throughout the fluorescent wavelength range of interest. The software also controls the delay line and gathers time-resolved information which is displayed in a 3D color plot. Calibrated GVD and photometric corrections of spectra are also automated in the software. Compared to pump-probe spectroscopy techniques such as transient absorption, the data interpretation of fluorescence upconversion is straightforward as only emission is measured. Fluorescence upconversion offers fs-resolved dynamics information over a range of 3.3 ns in the UV-VIS and IR spectral ranges.
For researchers interested in studying time dynamics out to µs time range, time-correlated single photon counting can be added primarily as an option for systems being pumped by femto or picosecond oscillators. TCSPC covers the UV-VIS wavelength ranges with high resolution. The TCSPC method is highly sensitive, so this will work well even for weak signals.
Fluorescence Upconversion provides 100-400 fs resolution*, time-resolved fluorescence kinetic trace data to study fast dynamics over standard 3.3 ns time scale.
Upconverted light is spectrally resolved to 150 cm-1**.
Luminescence Spectral Coverage over 400-1600 nm range standard***.
Software controls upconversion crystal angle (phase matching angle) and monochromator wavelength, delay line, data acquisition and spectral plots.
Automated, calibrated GVD and photometric correction of spectra.
Time-Correlated Single Photon Counting option extends time range window to 2 µs with 200 ps time resolution over 230-700 nm luminescent spectral range standard****.
* Time resolution is dependent upon width of gate pulse, thickness of upconversion crystal and fluorescent sample optical path length. Signal/noise increases with crystal thickness at a cost of time resolution.
** Spectral resolution is limited by gate pulse bandwidth and slit widths.
*** Dependent upon excitation and gate wavelengths; 800 nm gate assumed.
**** Other ranges possible, depending on PMT or single photon counting detector selected.
Fluorescence upconversion dynamics of Coumarin 153 in MeOH. (Courtesy Newport Technology & Applications Center)
Comparison of Fluorescence Upconversion to TCSPC for C153 in MeOH. (Fluorescence upconversion captures early dynamics while TCSPC captures extended time scale dynamics.)