Micro range imaging based on structured illumination

Quantitative characterization and imaging of three-dimensional (3D) microstructures using optical methods are of great concerns in both scientific research and practical applications, such as life science and micro systems technology (MST). A number of optical principles have been applied for different types of 3D microscopy. Laser scanning confocal microscope (LASCM), interferometric microscope (IM), Zernike phase contrast (ZPC), differential interference contrast (DIC), optical coherence tomography (OCT) and digital holographic microscope (DHM) are typical representatives for 3D micro imaging. Most of mentioned technique for 3D microscopy have been already commercialized and are currently available on the market. However, not all of those optical imaging methods are suitable for quantitative assessment of microstructures but only for qualitative observations with a few exceptions like DHM and IM. Quantitative analysis and characterization of 3D microstructures have become increasingly important as the development of microsystems, including micro-optics, micro fluidics and lab-on-chips. Structured illumination based range imaging on (SIRI) such as fringe projection profilometry has been widely used in industry and scientific research. Typical examples of range imaging in a variety of application fields include art, architecture, archeology, medical imaging, industrial inspection, reverse engineering, virtual reality, to name just a few. The SIRI works well in a moderate scale in terms of target size. In contrast with the SIRI in macro scale, the research of micro range imaging based on structured illumination (μSIRI) receives much less attention. However, the μSIRI could be a promising candidate for quantitative three-dimensional (3D) imaging in microscopy due to its unique features such as fast acquisition, high data density, and cost-effective configuration. This talk will address some important issues regarding the μSIRI as an enabling tool for quantitative 3D imaging in microscopy. The main issues to be discussed involve in reformulating the image formation of the μSIRI by introducing a concept of active micro stereoscopy, characterizing the lateral and longitudinal resolutions of the μSIRI microscopy in three dimensions and suggesting a strategy of calibration for the μSIRI microscope. Some preliminary experiment results are also presented to verify the presented approach.