Young probing fluorescence microscopy: Single-pixel imaging free of array-type actuators

Past realizations of single-pixel imaging have relied on array-type actuators to encode structural information in well-defined patterns in space, thus enabling image synthesis while circumventing the need for cameras. In microscopy, the binary response of grid-organized elements (typically mirrors in digital micromirror devices) have limited imaging resolution to 2.7 µm. Here, we introduce ‘Young probing’: A new probing strategy in single-pixel imaging that uses a few, simple deflection systems to form freely definable sinusoidal probe patterns across the object of interest, thus circumventing the drawbacks of array-type actuators for probing and cameras for detection. We demonstrate Young probing in single-pixel fluorescence microscopy, detailing calibration routines and methods for eliminating aliasing artifacts, and achieving an imaging resolution of 0.5 µm (>5-fold improvement). Thus, we push single-pixel imaging into a resolution regime suitable for capturing the morphology of biological cells, bringing into play projection imaging and volumetric probing with a signal-collection efficiency limited only by the numerical aperture of the imaging system. We demonstrate projection imaging of living cells and compatibility with spectral detection. Lastly, we discuss the general applicability of Young probing across other spectral regimes, contrasts, and types of radiation that are not readily supported by cameras or array-type actuators.