Monochromators are a common utility for the spectral calibration of spectrometers. To guarantee traceability of characterization measurements to SI-standards, monochromators used as secondary standards must be properly calibrated. Common calibration procedures are based on the measurement of spectral lines emitted by gas-discharge lamps or lasers. Due to the nature of these light sources, the sampling of calibration points cannot be freely chosen. In this paper we present an approach where an echelle grating wavelength meter (WM) is used to traceably calibrate the emitted center wavelength of a monochromator at almost any sampling interval. In addition, it is possible to calibrate the monochromator outside the sensitive spectral range of the WM used. It is demonstrated how a WM is calibrated and then how it is used to calibrate the monochromator of DLR's Calibration Home Base (CHB) for imaging spectrometers at DLR Oberpfaffenhofen, Germany. The same approach is also used for the monochromator, which is intended for the laboratory calibration of the German hyperspectral satellite mission EnMAP.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/OE.27.013596 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
We propose a spatial heterodyne Raman spectrometer (SHRS) based on a field-widened grating-echelle (FWGE). A normal grating is combined with an echelle grating in a conventional spatial heterodyne spectrometer to eliminate ghost images without using masks, and prevents interference among the spatial frequencies of different diffraction orders. Mathematical expressions and derivation processes are given for the spectral parameters in the FWGE-SHRS and a verification breadboard system is fabricated.
View Article and Find Full Text PDFAlignment of mosaic gratings is traditionally supported by two interferometric verifications: on the zero order to verify the grating surfaces and on the blaze to verify the groove direction. In the case of low frequency echelle grating an interferometric measurement on the zero order is hardly feasible due to extremely low contrast of the fringes. The complete alignment has then to be carried out on high order (close to the blaze) where the two misalignment errors (the tip and rotation) show the same effect on the interferogram.
View Article and Find Full Text PDFWe present a spectral-scanning frequency-modulated continuous wave (FMCW) 3D imaging system capable of producing high-resolution depth maps with an extended field of view (FOV). By employing a multipass configuration with an echelle grating, the system achieves an FOV of 5.5° along the grating axis.
View Article and Find Full Text PDFTool wear is one of the main causes of failure during diffraction grating ruling. However, no theoretical model for tool wear analysis has been available to date. A mathematical model is established here to solve for the friction coefficient at the tool contact position for the first time.
View Article and Find Full Text PDFDetection of microplastics via a confocal-microscope spatial-heterodyne Raman spectrometer with echelle gratings.
Spectrochim Acta A Mol Biomol Spectrosc
May 2024
Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, Jilin 130033, China; University of Chinese Academy of Sciences, Beijing 100049, China; National Engineering Research Center for Diffraction Gratings Manufacturing and Application, Changchun, Jilin 130033, China.
Microplastic pollution has become a global environmental problem that cannot be ignored. Raman spectroscopy has been widely used for microplastics detection because it can be performed in real-time and is non-destructive. Conventional detection techniques have had weak signals and low signal-to-noise ratios (SNR).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!