Wavelength meters are central for many applications such as in telecommunication systems or laser monitoring. The primary function of a wavelength meter is to provide an output signal that changes sensitively with the wavelength of the input light. Of central importance is the reproducibility of the output signal even in the presence of external perturbations, e.g., temperature changes causing thermal drift. Various different methods are usually applied to improve reproducibility, e.g., thermal stabilization or repeated calibration with an additional reference light source of well-known and stable wavelength.@en

Wavelength meters are central for many applications such as in telecommunication systems or laser monitoring. The primary function of a wavelength meter is to provide an output signal that changes sensitively with the wavelength of the input light. Of central importance is the reproducibility of the output signal over long time intervals during which external perturbations might negatively affect the reproducibility of the displayed wavelengths.@en