Super Bright Light-Emitting Diode for Optical Roughness Characterization

A promising in-process roughness measuring technique is based on the detection of polychromatic scattered light Distributions and speckle correlation algorithms. The spectral light properties mainly influence the measuring range and the resolution. Further approaches use lasers, laser diodes, or a superluminescant diode (SLD), to produce light beams with a discrete or continuous spectrum and a sufficient temporal coherence to generate speckles. The presented approach investigates the suitability of a low-cost super bright light-emitting diode (SLED) for roughness characterization.