Nontranslational three-dimensional profilometry by chromatic confocal microscopy with dynamically co
Nontranslational three-dimensional profilometry by chromatic confocal microscopy with dynamically configurable micromirror scanning.
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., 40x, 60x, and 100x) to achieve different system characteristics. With a 100x objective, the microscope acquires stable measurements over a 320 mum x 240 mum surface area with a depth resolution of 0.39 mum at a 3-Hz scan rate. The total longitudinal field of view is 26.4 mum for a wavelength tuning range of 48.3 nm. The FWHM value of the longitudinal point-spread function is measured to be 0.99 mum. 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.
Cha S, Lin PC, Zhu L, Sun PC, Fainman Y.