Optical arrangement e.g. surface sensor, for depth discrimination for performing topographic measurements, has etalon with better transmission or reflection in measurement areas than areas, which are deviated from measurement areas

摘要

The arrangement has an etalon (1) generating constructive or destructive interference in an optical path of an optical structure ad generating multi-beam interference. The element generates light of wavelengths from measurement areas. A detector records intensity of the constructive or destructive interference. The etalon has a better transmission or reflection in the measurement areas than in areas, which are deviated from the measurement areas. An independent claim is also included for an optical method for depth discrimination.