Broadband interferometric confocal microscope

A system for three-dimensional imaging of a sample, comprising:

• a beam splitter that splits an optical beam into a reference beam and a scanning beam;
• a scanner that focuses the scanning beam onto or within a section of a plurality of sections of the sample, each section producing a respective plurality of scattered beams;
• a phase modulator that modulates a phase of the reference beam;
• a beam attenuator located in an optical path of the reference beam for producing an attenuated reference beam;
• a confocal microscope that (i) includes an objective lens and (ii), for each of the plurality of sections, interferometrically combines the attenuated reference beam and the respective plurality of scattered beams and generates a respective one of a plurality of two-dimensional images;
• a validation window located between the objective lens and the sample and having (i) a transparent region, located directly above the sample, that allows the scanning beam and scattered beams from the sample to propagate unaltered;
• and (ii) a validation region that, when a beam waist of the scanning beam is located on validation features of the validation region, allows dimensional measurements of the validation features, the validation region not overlapping the transparent region;
• and
• a processor that generates a three-dimensional image of the sample based on the plurality of two-dimensional images.