The pinhole camera has inspired a lens-less, three-dimensional imaging technology that produces some of the brightest, sharpest X-ray holograms of microscopic objects to date. The technology was developed by scientists at the Advanced Light Source of the U.S. Department of Energyâ€™s Lawrence Berkeley National Laboratory, and at FLASH, the free-electron laser in Hamburg, Germany.
â€œOur purpose was to explore methods of making images of nanoscale objects on the time scale of atomic motions, a length and time regime that promises to become accessible with advances in free-electron lasers,â€ says Stefano Marchesini of the ALS, who led the research. â€œThe technique we used is called massively parallel x-ray Fourier-transform holography, with coded apertures. What inspired me to try this approach was the pinhole camera.â€
By knowing the precise layout of a pinhole array, including the different sizes of the various pinholes, a computer can recover a bright, high-resolution image numerically. According to Marchesini, putting a uniformly redundant array next to an object being imaged with the x-ray beam line creates a holographic image with orders of magnitude higher intensity than a standard hologram.