Hollow cathode lamps (HCLs) are excitation light sources commonly used in hydride generation atomic fluorescence spectrometry (HG-AFS). There are obvious Pb interfering lines at 217.0 nm, 261.3 nm, and 283.3 nm in the atomic fluorescence spectrum excited by Se HCLs. This will induce erroneously measured results especially when using the non-dispersive detection method when Se and Pb are detected simultaneously. To solve the spectral interference caused by Se HCLs, in this paper, a 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 is designed for dispersive atomic fluorescence spectrometry. In addition, a modified DMD with a cover window made of Corning HPFS® 7980 standard grade fused silica was used to provides a higher transmittance of 180–320 nm. The most attractive features of this UV digital micromirror spectrometer are its simple structure, high sensitivity, no macroscopic moving parts, and rapid spectral analysis (0.419 s per spectrum). After optimizing DMD and PMT control parameters, the effects of the chemical generation system (K₃Fe(CN)₆, KBH₄, and HCl) are investigated. The atomic fluorescence spectra of Se and Pb are obtained, and the detection limits of the analytical lines are discussed. The feasibility of the present method is confirmed by simultaneous detection of Se and Pb using water samples (GSBZ50031-94 and GSB07-1183-2000) and multi-element standard solution (GBW(E)080669) as reference materials. This study demonstrates the potential of the proposed spectrometer for dispersive HG-AFS, which appropriately reduces the purity requirements of the light source and the spectral interference from light sources. It is also applicable to simultaneous detection using multi-element HCLs or continuous light sources.

A tomographic microscopy system can achieve instantaneous three-dimensional imaging, and this type of microscopy system has been widely used in the study of biological samples; however, existing chromatographic microscopes based on off-axis Fresnel zone plates have degraded image quality due to geometric aberrations such as spherical aberration, coma aberration, and image scattering. This issue hinders the further development of chromatographic microscopy systems. In this paper, we propose a method for the design of an off-axis Fresnel zone plate with the elimination of aberrations based on double exposure point holographic surface interference. The aberration coefficient model of the optical path function was used to solve the optimal recording parameters, and the principle of the aberration elimination tomography microscopic optical path was verified. The simulation and experimental verification were carried out utilizing a Seidel coefficient, average gradient, and signal-to-noise ratio. First, the aberration coefficient model of the optical path function was used to solve the optimal recording parameters. Then, the laminar mi-coroscopy optical system was constructed for the verification of the principle. Finally, the simulation calculation results and the experimental results were verified by comparing the Seidel coefficient, average gradient, and signal-to-noise ratio of the microscopic optical system before and after the aberration elimination. The results show that for the diffractive light at the orders 0 and ±1, the spherical aberration W040 decreases by 62–70%, the coma aberration W131 decreases by 96–98%, the image dispersion W222 decreases by 71–82%, and the field curvature W220 decreases by 96–96%, the average gradient increases by 2.8%, and the signal-to-noise ratio increases by 18%.

Sequentially timed all-optical mapping photography is one of the main emerging ultra-fast detection technologies that can be widely applicable to ultra-fast detection at the picosecond level in fields such as materials and life sciences. We propose a new optical structure for an all-optical spatial mapping module that can control the optical field of two-dimensional imaging while improving spectral resolution and detector sensor utilization. The model of optical parameters based on geometrical optics theory for the given structure has been established, and the theoretical analysis of the inter-frame energy crosstalk caused by incident beam spot width, chromatic aberration, and main errors of the periscope array has been conducted. The optical design of the two-dimensional (2D) all-optical spatial mapping module was finally completed using ZEMAX OpticStudio 2018 software. The results show that our optical module can realize targets of 16 frames and 1.25 nm spectral resolution.

Correction for ‘A UV digital micromirror spectrometer for dispersive AFS: spectral interference in simultaneous determination of Se and Pb’ by Chen Tao et al., J. Anal. At. Spectrom., 2018, 33, 2098–2106.