Research on Dispersive Detection Technology Based on Digital Micromirror Device by Atomic Fluorescence Spectrometry

A ultraviolet (UV) digital micromirror spectrometer using a digital micromirror device (DMD) as a spatial light modulator, a grating as a spectroscope and a photomultiplier tube (PMT) as a detector, was specially designed for dispersive hydride generation atomic fluorescence spectrometry (HG-AFS). To improve the detection ability of the UV digital micromirror spectrometer for weak fluorescence signals at 180-320 nm, a high UV transmittance DMD was used and the signal acquisition system was improved, and the control parameters of DMD and PMT negative high voltage were optimized. The feasibility of the spectrometer was demonstrated with standard sample analyzing of As, Sb, Bi, and Hg, the emission and atomic fluorescence spectra were obtained, and the scattering interference caused by the light source was discussed. The results showed that the UV digital micromirror spectrometer had a preliminary ability for the excitation fluorescence analysis by HG-AFS. In addition, due to no macroscopic moving parts, the UV digital micromirror spectrometer had simple construction and fast analysis speed (0.848 s per spectrum scan).