System for wavelength-dependent spectroscopy and method for evaluating measurement signals in wavelength-modulated spectroscopy

摘要

In a system for wavelength-modulated spectroscopy, in particular for absorption and emission spectroscopy, comprising a signal evaluation device with a signal input, a mixing device and a local oscillator for generating a time-dependent local oscillator signal, which mixing device is coupled to the signal input and the local oscillator for generating one time-dependent demodulation signal by mixing a time-dependent input signal present at the signal input and the time-dependent local oscillator signal to improve the evaluation of input signals when using mixing devices, it is proposed that the local oscillator be designed to generate the time-dependent local oscillator signal in Form of a time-dependent trigonometric function, which is formed by additive superposition of at least two time-dependent trigonometric functions. Furthermore, an improved method for Au suggested measurement signals.