Resolution enhancement by subpixel sampling and computational reconstruction

Image resolution and field of view in far-field optical microscopy are often inversely proportional to one another due to digital sampling limitations imposed by the magnification of the system and the pixel size of the sensor. We present a method including a spatial shifting mechanism and a reconstruction algorithm that bypasses this trade-off by shifting the sample to be imaged by subpixel increments, before registering the images via phase correlation and combining the resulting registered images using the shift-and-add approach. Importantly, this method requires no specific optical components that are uncommon to commercially available or custom-built microscope systems. The findings of the presented study demonstrate an improvement to spatial resolution of ∼42% while maintaining the system's field of view (FOV), leading to a more than twofold improvement to the system's space-bandwidth product (SBP).