Fig. 1

Rows a, b and c of the first column depict different illumination patterns exciting yellow green fluorescent particles in a glass capillary. Detection objectives 1 and 2 capture two orthogonal scenes of the sample as shown in columns 2 and 3. The color scales are in arbitrary units. a Wide-field excitation results in images blurred by out of focus signal. b Light sheet illumination excites a thin sheet in y–z plane. Detection objective 2 captures a sharp image with negligible out of focus contribution. Detection objective 1 captures a line shaped image. Most of the signal comes from the thinnest part of the sheet with highest intensity. c A scattering layer scrambles the illumination into a speckle pattern regardless of its original shape. The resulting images again suffer from out of focus blurring. Note, that detection objective 1 is mainly responsible for providing feedback signal for the optimization to recover a light sheet type illumination behind scattering layer. Nevertheless, it can be used for fluorescence detection as well