FPA spectrograph for the MIR
As the result of the availability of high sensitive Focal Plane Arrays (FPA) in the Mid-Infrared (MIR) spectral range, the concept of a dispersive Echelle spectrograph becomes feasible now. It supplements standard FTIR spectrometers especially in view of the detection of transient signals (e.g. protein folding kinetics) in snapshot mode. We expect measurement times of typically 0.5 ms to 10 ms per full spectrum with improved signal-to-noise ratio due to spectrometer operation in a cryovacuum tank.
The new spectrometer concept, exploiting the two-dimensional structure of the detector for increased spectral resolution, will provide fast measurement of a broad spectral range with parallel spectral acquisition, which is important to a wide range of biological and medical research areas. Chemical imaging (IR microscopy) of samples over a range of 100 x 100 pixels will be achieved with diffraction limited lateral resolution within a few seconds. As background radiation sources for microscopy applications, the infrared beam lines at Bessy II and MLS/PTB, but also thermal sources, are planned to be used. Using a prototype, the functional principle of the compact spectrograph could be experimentally verified in 2010 by means of the recording of first echelle spectra.