Transient Absorption Spectrometer, also called Flash Photolysis Spectrometer is dedicated to measure transitions between quantum states in sample. Solid state sample in ground state is energized to excited state by intensive laser pulse and immediately deexcitates back to ground state. Process of deexcitation is monitored by measurement of the absorption of the white light in liquid samples or by measurement of the light reflected by the solid state sample.

Solid state samples may be submerged in electrolyte and its polarization potential may be set during the measurement.

System provides functionality that enables measurement of fluorescence and phosphorescence excited by laser pulse.

Measurement system operation is very intuitive, dedicated software provides completely automated experimental procedures.

Quantities measured by the instrument:

• Transmitance/absorption or reflectance spectrum of the sample,
• Emisive fluorescence spectrum of the sample,
• Duration of the excited states generated in the sample by laser pulse,
• Laser beam intensity on input and output of the sample chamber,
• current-voltage characteristics of the electro-chemical samples.

1. Closed sample chamber.
2. Xenon lamp with water cooling system and pulser.
3. Laser, typically Nd:YAG with possibility of choosing higher harmonics.
4. Monochromator for UV, VIS and IR spectrum range.
5. Osciloscope.
6. Photomultiplier.
7. Timer synchronizing all the components of the system.
8. Potentiostat providing full characteristics of the electro-chemical sample.
9. Electro-chemical cuvette with platinum electrode and Ag/AgCl reference.
10. Computer with dedicated FotoGUI software.

White light source:

The source of the white light is xenon lamp  that radiates electro-magnetic light in UV, VIS and NIR range.

Incident white light may be modified with filters, including Air Mass Filter, which provides standardized parameters of sun-like light. Filters may by also used on the output of the sample chamber (monochromator input).

White light beam passing throught the sample or falling on the solid state sample is a parallel beam with several mm diamater (diamater may be adjusted to the experiment requirements).

Sample chamber

Sample chamber provides isolation of the measurement setup from background diffused light.  It is equipped with safety system that disconnects power supply of the xenon lamp and laser source after opening the chamber and system of easy and stable installation of several different experimental setups.

Inner measurement setups with different optical paths and sample cuvettes may be provided and adjusted to the individual experimental requirements.

Parallel white light beam and laser beam passing through the sample.

Perpendicular passing of the white light beam and laser beam through the sample.

Measurement of solid state sample reflectance spectrum.