We present a new folded dual-view oblique plane microscopy (OPM) technique
termed dOPM that enables two orthogonal views of the sample to be obtained by translating a
pair of tilted mirrors in refocussing space. Using a water immersion 40× 1.15 NA primary
objective, deconvolved image volumes of 200 nm beads were measured to have full width at
half maxima (FWHM) of 0.35±0.04 μm and 0.39±0.02 μm laterally and 0.81±0.07 μm axially.
The measured z-sectioning value was 1.33±0.45 μm using light-sheet FWHM in the frames of
the two views of 4.99±0.58 μm and 4.89±0.63 μm. To qualitatively demonstrate that the system
can reduce shadow artefacts while providing a more isotropic resolution, a multi-cellular
spheroid approximately 100 μm in diameter was imaged.