Bruker has introduced a beamsplitter which covers the complete mid and far Infrared/THz spectral ranges.
Bruker claims that this is an FTIR world first offering coverage of the complete mid and far Infrared/THz spectral ranges in one go with no gaps.
The new wide band beamsplitter T240/3 is offered for the Bruker VERTEX 70 entry level research FTIR spectrometer series and allows all common IR measurement techniques to benefit from full spectral range coverage from 6000 cm-1 to 10 cm-1 without the need of any beamsplitter exchange.
The spectral range of an FTIR spectrometer is mainly defined by its choice of source, beamsplitter and detector combination.
The lower limit of the spectral range is very dependent upon the beamsplitter and is typically limited to 350 cm-1 (KBr) or 200 cm-1 (CsI).
To extend the spectral range further into the far IR and THz spectral ranges one or more additional far IR beamsplitters are required and because of these needs the user has to open manually the access flap in the spectrometer optics bench.
But now Bruker can offer for the first time a wide spectral range beamsplitter which, in connection with a single DLaTGS detector and source, enables access to the spectral range from 6000 cm-1 down to 130 cm-1 in one step for all types of transmittance, reflectance and ATR measurements.
The new optical device complements the automatic beamsplitter changer unit BMS-c for the VERTEX 80 high end research FTIR spectrometer series which was introduced by Bruker in 2010.
When the VERTEX 70 or VERTEX 70v spectrometers are equipped with a second detector position and far IR DTGS detector, using the same beamsplitter, the spectral range can be extended down to 30 cm-1 completely under software control.
This automatic mode is even possible down to 10 cm-1 with an externally adapted mercury arc lamp and automatic source switching.
The extension of the mid IR towards the far IR spectral range below 400 cm-1 is of general interest for molecular vibrational analysis in inorganic and organometallic chemistry as well as for geological, pharmaceutical and physical applications.
The ATR measurements of Calcium Carbonate (red curve) and Ascorbic Acid (blue curve) shown here demonstrate that with the Bruker VERTEX 70 or VERTEX 70v FTIR spectrometers and the new wide band beamsplitter T240/3 the spectral range from 4000 cm-1 to 130 cm-1 is covered in a single step.