An interference microscope based on a wavelength-to-depth encoding technique is presented. The wavelength-to-depth encoding is realized by using a diffractive lens and wavelength tuning. The coherence degree of the interference fields versus wavelength is analyzed. A depth discrimination of 0.71 μm is obtained with 0.90 NA objective lenses. Experimental results of a four-level grating measurement are presented with results are comparable to those obtained with a Dektak profilometer and the same interference microscope using mechanical depth-scanning. The system is promising for fast, noncontact, high-resolution three-dimensional imaging.
