C11367-31 Quantaurus-Tau Fluorescence Lifetime Spectrometer from Hamamatsu Photonics

The Quantaurus-Tau is a compact system for quickly and easily measuring the fluorescence lifetime of photoluminescent materials from sub-nanoseconds to the millisecond range, with single-photon-counting sensitivity. Samples in different forms―thin films, solids, powders, and solutions―can be analyzed. Liquid samples can be cooled down to -196 deg.C (77K) with liquid nitrogen.

Operation is simple. Just load the sample into the sample chamber. Then enter a few conditions on the measurement software to measure the fluorescence lifetime and photoluminescence (PL) spectrum. It only takes a minute to get analysis results for a typical measurement. The measurement software includes a variety of measurement and analysis functions such as multicomponent analysis and multisample data comparison.


  • Fluorescence lifetime measurement
  • Measuring an excited-state relaxation process
  • Easy and quick measurements
  • 7 excitation wavelength
  • Analyzing different sample forms
  • Wavelength: 300 nm to 800 nm
  • High sensitivity measurement by photon counting method
  • Time resolution better than 100 ps (by deconvolution)
  • Cooling function for solution sample (-196 °C) (option)
  • Phosphorescence measurement (option)
  • Fluorescence spectrum measurement
  • Space-saving, compact design

Relationship between quantum yield and fluorescence lifetime

The Jablonski energy diagram on the right shows the electronic energy levels of general organic molecules and indicates a few electronic transitions between the energy levels. S0, S1 and T1 represent the ground state, the lowest singlet state, and the lowest triplet state, respectively. After photoexcitation, the molecule in the excited state deactivates to the ground state via several relaxation pathways which are classified into radiation and radiationless processes. The radiation process involves the emission of radiation such as fluorescence and phosphorescence. The radiationless process involves internal conversion and intersystem crossing followed by thermal release. The radiation and radiationless processes compete with each other.

When the rate constants for fluorescence, internal conversion, and intersystem crossing are abbreviated by kf, kic, and kisc, respectively, the fluorescence lifetime Τf is expressed by the following equation.

Τf = 1/ (kf + kic + kisc) (1)

On the other hand, fluorescence quantum yield Φf is expressed as the equation below.

Φf = kf / (kf + kic + kisc) (2)

Thus, equation (3) is derived from equations (1) and (2).

kf = Φf / Τf (3)

You can see from the above equations that there is a close relationship between the fluorescence lifetime and quantum yield, and these parameters are fundamental and very important in controlling the emission properties of luminescent materials.

Hamamatsu has developed the Quantaurus series for a diversified evaluation of luminescent materials. Quantaurus-Tau and Quantaurus-QY are now available for measuring fluorescence lifetime and quantum yield, respectively. Complementary analyses with the two systems enable users to promote development of photoluminescent materials.

Detail information for absolute PL quantum yields measurement system Quntaurus-QY, you can get it from recommended product area in the below.


Type number



Solution, Thin-film

Detector type


Wavelength range

300 nm to 800 nm

Excitation light source

Seven types of LED light source (280 nm, 340 nm, 365 nm, 405 nm, 470 nm, 590 nm, 630 nm)

Excitation light source switching

Software control


Czerny-Turner monochromator

Measurement time range

4 ns to 10 s / full scale

Phosphorescence measurement

Phosphorescence excitation wavelength (280 nm, 340 nm, 365 nm, 405 nm, 442 nm, 470 nm, 589 nm, 632 nm)

Time axis channel

512 ch, 1024 ch, 2048 ch, 4096 ch

Total time resolution

< 1.0 ns FWHM (IRF with 365 nm LED)

Analysis function

Fluorescence lifetime analysis (up to five components by exponential function fitting) and spectrum analysis

Supported OS

Windows 7 (32 bit), Windows 7 (64 bit)