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Rationale: Atmospheric pressure interface multi‐reflection time‐of‐flight mass spectrometry (API‐MRTOF‐MS) has the potential to be a rapid and high‐resolution analytical tool for versatile applications in chemistry, biology, environmental science, and medicine. Methods: The ions were reflected in a mass analyzer via electrostatic mirrors and folded flight path. Therefore, flight distances were significantly increased. The ion flight path of the API‐MRTOF‐MS was extended from meters to over 1 km, and the mass resolution was increased. Furthermore, the mass analysis could be completed at around 10 ms due to the rapid response of TOF‐MS. Results: A high‐resolution API‐MRTOF‐MS approach is successfully developed in this study. The mass resolution could achieve 116 050 (full widths at half maximum [FWHM]) for Cs+ ions using an atmospheric pressure electrospray ionization within a total TOF of only 18 ms. An ion transmission efficiency of over 50% was achieved after 600 cycles. Conclusions: The analytical performance of the newly developed API‐MRTOF‐MS demonstrated that it is suitable for high resolution and rapid analysis in many fields. [ABSTRACT FROM AUTHOR]

Iron-doped binary chalcogenide crystals are very promising for tunable solid-state lasers operating over the 3~5 μm spectral range. Fe: ZnSe is one of the most important gain crystals with the obvious advantages of material characteristics and conversion efficiency. By adjusting the output mode of the pump source, an Fe: ZnSe laser can operate in two modes at liquid nitrogen temperatures: continuous wave (CW) and pulse output. In terms of CW output, the Fe: ZnSe laser obtained a maximum 2.63 W continuous power output which was confined to the power of the pump source. An optical-to-optical efficiency of 47.05% was acquired. Direct electrical modulation was applied to the pump source. The highest average power of the quasi-CW laser, whose central wavelength is 4.02 μm, has a value of 253 mW with an optical-to-optical efficiency of 42.88% and a full width at half maximum (FWHM) of 23 nm when the pulse frequency is 100 Hz of 10% duty factor. The output waveform is consistent with the modulation waveform applied to the pump source. We report to the first of our knowledge an electrically modulated quasi-CW Fe: ZnSe laser in the pulse regime, equipped with features of compactness in structure, ignoring additional modulators, convenience in control, high efficiency, and sustainable operation, of great interest for solving numerous scientific and applied problems. [ABSTRACT FROM AUTHOR]