A compact raster lensless microscope based on a microdisplay

Open Access

Abstract

Lensless microscopy requires the simplest possible configuration, as it uses only a light source, the sample and an image sensor. The smallest practical microscope is demonstrated here. In contrast to standard lensless microscopy, the object is located near the lighting source. Raster optical microscopy is applied by using a single-pixel detector and a microdisplay. Maximum resolution relies on reduced LED size and the position of the sample respect the microdisplay. Contrarily to other sort of digital lensless holographic microscopes, light backpropagation is not required to reconstruct the images of the sample. In a mm-high microscope, resolutions down to 800 nm have been demonstrated even when measuring with detectors as large as 138 μm × 138 μm, with field of view given by the display size. Dedicated technology would shorten measuring time. ; This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 737089 and from the Ministry of Science and Innovation, the Spanish State Research Agency and the European Regional Development Fund through project PID2019-105714RB-I00.