Transient absorption spectrometer

An integrated spectrometer capable of measuring transient absorption of electron states by nanosecond laser flash photolysis in the UV-VIS-IR range.

Excitation light source 1. A tunable optical parametric oscillator pumped with a nanosecond Nd:YAG source 2. Pulse frequency of 10Hz; a pulse length of no more than 5 ns. 3. Beam energy at 260 nm not less than 6.5 mJ, 340 nm,not less than 10 mJ, 450 nm not less than 60 mJ. 4 Tuning resolution of 1 cm-1 in the range 410-2600 nm and 2 cm-1 below 410 nm. 5 Spectral linewidth for 410 - 2600 nm: not more than 5 cm-1. 6 Beam divergence < 2 mrad (@ 450 nm). 7.Control from external display or computer.

Monochromator 1. Monochromator of the Czerny-Turner type with a focal length of at least 325 mm placed in the emission path. 2. Diffraction grating carousel for UV-VIS and NIR range; Spectral resolution of 0.1 nm for UV-VIS range. 3. Automatically adjustable slits 4. Spectral dispersion of 1.66 nm/mm for kinetic measurements at one wavelength in the range 230-980 nm. 5. Scanning speed of 200 nm/s.

Detection system (a) Thermoelectrically cooled photomultiplier with gain level control. Range at least 230 to 980 nm. Photomultiplier response time of not more than 5 ns. (b) Thermoelectrically cooled InGaAs detector. Range from 900 to 2050 nm. Photomultiplier response time of no more than 100 ns.

Optically isolated sample chamber with cover; two independent sockets to accommodate measurement attachments; automatic laser beam shutter.