Measurement of 3D Printed Structure Using a Peak Detection Method in Dispersive Interferometry

We describe an optical three dimensional (3D) measurement method using white-light dispersive interferometry in the range of 5 μm–150 μm. A spectrometer was employed for real-time wavelength scanning and the distance information was obtained using a simple peak detection method in the spectral domain. Fast measurement time enabled us real-time distance measurement of the specimen. The piezoelectric actuator and capacitance distance sensor was employed for nanometer positioning and measuring distance reference value. This technique can be implemented as a distance measurement unit in white-light scanning interferometry by simply attaching a spectrometer to the conventional system. The results showed an accuracy of better than 60 nm for any position within 5 μm–150 μm. The proposed technique can be used as shape-measuring tool for 3D printed products. Measurement results using the proposed method are also presented. These experimental results show that pthe roposed method can be used as a measurement tool for 3D printed products.