Ultra-compact and large field-of-view nano-illumination light microscope based on an array of organic light-emitting diodes

Nano-Illumination Microscopy (NIM) is a technique that provides compact microscopes but at the present time only setups with limited Field-of-View (FOV) have been presented. Existing NIM setups reconstruct the image by measuring the light intensity that passes through the specimen when switching after one another the light emitting diodes (LEDs) on an array. The resolution of NIM is related to the LEDs pitch, while the FOV to the total area covered by the array. The first prototypes were demonstrated with 10 μm-pitch GaN-based 8x8 LED arrays giving rise to 80x80 μm2 FOV. This work presents the first electronically-activated Scanning Transmission Optical Microscope (eSTOM) built with an Organic LED-on-silicon micro-display with 5 μm LEDs pitch, providing a FOV of 3.6 × 1.28 mm2 . It is combined with a CMOS optical sensor with no other optical or mechanical components. We demonstrate how downscaling of the OLED array by means of optical lenses allows to further reduce the size of the light sources to explore the technique in more detail. Here we show steps towards the utility of NIM as a practical, low-cost and compact microscopy technique for biophotonics and many other applications.