Improving Spectroscopic Techniques by a Scanning Multichannel Method

Abstract

The conventional optical multichannel technique (MT) has improved optical spectroscopy, in comparison to single-channel methods, by at least an order of magnitude in measurement time at the same signal-to-noise ratio. In this work we show that some disadvantages (e.g., limited range of the recorded spectra, different noise and sensitivity of each detection element, and fixed spectral distance of the detection elements) can be excluded by using what we call the scanning multichannel technique (SMT). A calculation of the measurement time for characteristic single-channel and multichannel detectors results in the fact that SMT is, like MT, an order of magnitude faster than the single-channel technique (SCT). In some particular cases SMT results in measurement times shorter than those for MT. We conclude that SMT combines the advantages of MT and SCT. Moreover, measurements of sharp spectral lines made it evident that SMT also improves the reproducibility of the spectrometer used and increases the accuracy of the recorded spectra. The SMT method is not only restricted to optical spectroscopy but can be universally applied to all spectroscopic methods where multichannel detection is used.