A confocal microscope profilometer, which incorporates chromatic depth scanning with a diffractive optical element and a digital micromirror device for configurable transverse scanning, provides three-dimensional (3D) quantitative measurements without mechanical translation of either the sample or the microscope. We used a microscope with various objective lenses (e.g., 40×, 60×, and 100×) to achieve different system characteristics. With a 100× objective, the microscope acquires stable measurements over a 320 µm × 240 µm surface area with a depth resolution of 0.39 µm at a 3-Hz scan rate. The total longitudinal field of view is 26.4 µm for a wavelength tuning range of 48.3 nm. The FWHM value of the longitudinal point-spread function is measured to be 0.99 µm. We present 3D measurements of a four-phase-level diffractive element and an integrated-circuit chip. The resolution and the accuracy are shown to be equivalent to those found with use of conventional mechanical scanning.
© 2000 Optical Society of America
Original Manuscript: October 28, 1999
Revised Manuscript: February 10, 2000
Published: June 1, 2000
Sungdo Cha, Paul C. Lin, Lijun Zhu, Pang-Chen Sun, and Yeshaiahu Fainman, "Nontranslational three-dimensional profilometry by chromatic confocal microscopy with dynamically configurable micromirror scanning," Appl. Opt. 39, 2605-2613 (2000)