Dual-mode optical microscope based on single-pixel imaging

• Published in: Optics and lasers in engineering 2016-07, Vol.82, p.87-94
• Main Authors: Rodríguez, A.D., Clemente, P., Tajahuerce, E., Lancis, J.
• Format: Article
• Language: English
• Subjects: Arrays; Complement; Computational imaging; Devices; Illumination; Imaging; Microscopes; Microscopy; Optical microscopes; Reflection; Resolution; Transmission
• ISSN: 0143-8166; 1873-0302
• DOI: 10.1016/j.optlaseng.2016.02.004

We demonstrate an inverted microscope that can image specimens in both reflection and transmission modes simultaneously with a single light source. The microscope utilizes a digital micromirror device (DMD) for patterned illumination altogether with two single-pixel photosensors for efficient light detection. The system, a scan-less device with no moving parts, works by sequential projection of a set of binary intensity patterns onto the sample that are codified onto a modified commercial DMD. Data to be displayed are geometrically transformed before written into a memory cell to cancel optical artifacts coming from the diamond-like shaped structure of the micromirror array. The 24-bit color depth of the display is fully exploited to increase the frame rate by a factor of 24, which makes the technique practicable for real samples. Our commercial DMD-based LED-illumination is cost effective and can be easily coupled as an add-on module for already existing inverted microscopes. The reflection and transmission information provided by our dual microscope complement each other and can be useful for imaging non-uniform samples and to prevent self-shadowing effects.