Programmable high-speed confocal reflectance microscopy enabled by a digital micromirror device

The digital micromirror device (DMD) has been used to achieve parallel scanning in confocal microscopy significantly increasing acquisition speed. However, for confocal reflectance imaging, such an approach is limited to mostly surface imaging due to strong backreflections coming from the DMD that can dominate the signal recorded on a camera. Here, we report on an optical configuration that uses separate areas of DMD to generate multiple spots and pinholes and thereby prevents backreflections from the DMD from reaching the camera. We thus demonstrate confocal imaging of weakly reflecting objects, such as a pollen grain sample.