Method and device for measuring optical thickness

Abstract

An optical thickness measuring device includes a light source, a measuring head, an optical spectrometer with an optical component for spectrally splitting an input light, a detector, and an evaluation device. The light source is optically connected to the measuring head and is configured to generate an at least low-coherence measuring light and to direct it to the measuring head. The measuring head is optically connected to the spectrometer and is configured to direct the measuring light onto a measuring object and to direct light reflected therefrom, which originates from two different surfaces, onto a measuring object, which originates from two different surfaces, and to direct the reflected light to the spectrometer as input light. The spectrometer is electrically connected to the evaluation device and is configured to generate a spectrum of the reflected light, which originates from the two different surfaces of the measurement object and interferes with one another, and to send the spectrum to the evaluation device as an electrical signal. The evaluation device is configured to determine a distance between the two surfaces—i.e. the thickness of the measurement object.