Digital holographic microscopy for nanometric quality control of micro- optical components
In this paper, Digital Holographic Microscopy (DHM) is presented as a powerful tool for quality control of micro-optical components. It will be shown that not only the single-shot full field-of-view nanometer axial resolution makes DHM an ideal solution for such samples, but the DHM numerical wavefront correction formalism is perfectly adapted to provide advanced features like aberration coefficients, radius of curvature or optical surfaces roughness measurements. Both transmission and reflection configurations can be used depending of the micro-components under investigation. A transparent high aspect-ratio micro-components investigation procedure is also exposed in order to unable phase unwrapping. Each feature is illustrated with typical examples, ranging from a wide variety of micro-lenses (aspherical, cylindrical, squared) to cornercube micro- structures or diffractive elements.