Grating monochromator wavelength calibration using an echelle grating wavelength meter

Area of Science:

• Optical Engineering
• Metrology
• Spectroscopy

Background:

• Monochromators require accurate spectral calibration for traceable characterization measurements.
• Current calibration methods using gas-discharge lamps or lasers have limitations in sampling flexibility.

Purpose of the Study:

• To present a novel method for traceable calibration of monochromator center wavelengths.
• To enable flexible sampling intervals and calibration outside the wavelength meter's sensitive range.

Main Methods:

• Utilizing an echelle grating wavelength meter (WM) for calibration.
• Demonstrating the calibration process on DLR's Calibration Home Base (CHB) and for the EnMAP mission.

Main Results:

• Achieved traceable calibration of monochromators at almost any sampling interval.
• Successfully calibrated monochromators outside the sensitive spectral range of the WM.
• Applied the method to calibrate instruments for imaging spectrometers and the EnMAP hyperspectral satellite mission.

Conclusions:

• The presented approach offers a flexible and accurate method for monochromator calibration.
• This technique enhances the traceability of spectral measurements for scientific applications.
• The method is suitable for calibrating critical instruments for Earth observation missions.