Chromatic Confocal Principle
A chromatic confocal displacement sensor emits broadband light through a dispersive optical system. Different wavelengths focus at different positions within the measuring range, and each wavelength corresponds to a specific distance value.
When light reaches the target surface and is reflected back, only the wavelength that satisfies the confocal condition passes through the pinhole and is detected by the spectrometer. The controller then calculates the distance from the detected focal wavelength.
Interferometric Thickness Measurement
Interferometric measurement is based on spectral analysis of white-light interference signals. It is an important concept in optical inspection instruments, including chromatic confocal sensors and other high-precision thickness measurement systems.
By analyzing the interference signal observed by the spectrometer, the system can measure the optical path difference between interfaces and calculate the air gap or sample thickness.
Measurement Modes
In practical applications, chromatic confocal systems can support height measurement, single-sided thickness measurement, opposed thickness measurement, and multilayer thickness analysis depending on the sensor configuration and material properties.
These measurement modes make chromatic confocal technology suitable for glass, film, coating, semiconductor, battery, and precision component inspection where high resolution and non-contact measurement are required.