Traditionally, confocal imaging strategies use a small pinhole aperture at the imaging plane to reject scattered light and light that is out of focus from the optical plane of best focus. We describe a new imaging detection scheme that incorporates a digital micromirror device (DMD) at the imaging plane to provide a fast dynamic “synthetic aperture” through which different components of detected light in the imaging plane can be tuned by spatially changing an array of micromirrors. A DMD is a computer-controlled array of micromirrors that traditionally has been used to spatially control light in digital projectors.
We present a new application that uses the same device to extend the imaging capabilities of confocal imaging devices. In this paradigm, the DMD device reflects the spatial arrangement of light in the Airy pattern to one or multiple detectors. By diverting components of the Airy pattern into multiple detectors, we can optically or by means of software recombine the light via mathematical transforms to reconstruct different components of singly and multiply scattered light from the interrogated specimen. This detection scheme allows for all light at the imaging plane to be collected rather than just the light in the central pinhole configuration.
Video on this technology.