Miniaturized interferometric confocal distance sensor for surface profiling with data rates at ultrasonic frequencies

Point-wise measuring profilometers like the tactile stylus instruments or optical sensors are established measurement tools in science and industry to measure and characterize surface textures. We present a fiber-coupled laser interferometric confocal distance sensor for surface profiling. The sensor is characterized by small geometric dimensions and by its high lateral scanning speed. The ability to measure specularly reflecting and rough surface textures are demonstrated by performing several measurements on a sinusoidal standard as well as two roughness standards specified by different degree of roughness using various lateral scan velocities up to 75 mm s-¹. These measurement results are compared to those obtained by a tactile stylus instrument used in the identical measurement environment as the introduced optical sensor. Finally, the ability for full-field measurements is presented.