Spectrometer for laser flash photolysis

The client requested a system for measuring transient absorption using the pump & probe method with a perpendicular arrangement of the excitation and probe beams. The spectrometer had to include a xenon lamp (probe beam source) with a pulse unit, a sample chamber with a holder for standard spectroscopic cuvettes, a Czerny-Turner monochromator with a focal length of at least 325 mm, and a photomultiplier with a spectral range of at least 200–870 nm. A modular Q-switched Nd:YAG laser (1064 nm, min. 450 mJ) containing removable modules for generating second, third, and fourth harmonic frequencies (min. 130 mJ at 355 nm, min. 60 mJ at 266 nm) was to be used for excitation.

For this task, we chose the LP980-K modular spectrometer (manufactured by Edinburgh Instruments) for measuring nanosecond, microsecond, and millisecond transient absorption using the pump-probe method. The probe beam source is a broad-spectrum 150 W Xe lamp (230 nm to >900 nm) with the option of switching between continuous and pulse modes. Excitation is provided by a modular Nd:YAG laser with outputs at 1064 nm (min. 450 mJ), 532 nm (min. 220 mJ), 355 nm (min. 130 mJ), and 266 nm (min. 60 mJ). The sample chamber contains a holder for spectroscopic cuvettes. The spectrometer uses a Czerny-Turner monochromator with a focal length of 325 mm, which is equipped with a sensitive photomultiplier (spectral range 200-870 nm).