Color Volumetric Imaging With High Dynamic Range Based on Parallel Confocal Detection

Reflectance confocal microscopy is widely used in several applications that require non-destructive optical three-dimensional (3D) imaging. However, the acquisition speed of conventional confocal microscopy is limited by mechanical 3D scanning. Furthermore, acquiring data from a sample with excessively different degrees of reflectance is difficult. We propose a system that combines the high dynamic range (HDR) technique and parallelized confocal detection to achieve high-speed volumetric imaging for samples with varying reflectivity. Our technique sequentially acquires two-dimensional color images by projecting patterns onto the objects and using a focus tunable lens for axially scanning, thereby creating a volumetric profile. By modulating the power of the light source in synchronization with the axial scanning direction, two volumetric profiles are produced and fused them to reconstruct an HDR volumetric profile. We demonstrate that the proposed technique can capture thorough 3D profiles of samples even with a wide range of reflectivity.