LOW-COHERENCE FIBEROPTIC SENSOR WITH A LARGE NUMERICAL APERTURE FOR TOPOGRAPHIC MEASUREMENTS

We describe a compact fiber-optic setup for three-dimensional topometr y. The measuring principle is based on low-coherence interferometry in combination with a confocal microscope. Integrating an optical arrang ement based on compact disk optics together with fiber optics into one sensor yields a compact unit. The sensor has a numerical aperture of 0.45 and is suitable for measuring large surface slopes with high spat ial resolution. Further, a depth measuring range of more than 1 mm can be achieved. The capabilities of our setup for three-dimensional meas urements are demonstrated. (C) 1998 Optical Society of America.