Fig. 2.

Characterization of the tunable laser sheet of PIP. (a) Tuning the laser sheet thickness simply by adjusting the diaphragm. As the beam width decreases through reducing the aperture size of diaphragm from 1.8 mm (top) to 1 mm (bottom), the laser sheet becomes less focused and linearly thicker at the waist. The scale bars are 200 μm in i to ii, and 10 μm in inserts, respectively. (b) The corresponding change of the confocal region, which represents the available area for light sectioning. The double-headed arrow line shows the length of the confocal range (x direction), within which the light sheet can be considered uniform. The length of the confocal range is inversely proportional to the square of the light sheet thickness. The scare bars are 100 μm.