Lj1558rm a

We developed two different light-sheets for use with the Mesolens. The first was a simple and long but relatively thick light-sheet using Gaussian optics. The second was a propagation-invariant light-sheet using an Airy beam, which covers the same area as the Gaussian light-sheet but is a fraction of the thickness for improved optical sectioning. A Coherent Sapphire 488-10 CDRH laser emitting light at 488 nm with a maximum of 10 mW average power at the sample plane was used as light source used for both light-sheet illuminators. The Gaussian light-sheet was formed by directing the 8 mm expanded beam through a cylindrical lens (f = 300 mm. LJ1558RM-A, Thorlabs). The Airy light-sheet was shaped with the following optical elements: two aspherical lens (AL, f = 20 mm. AL2520-A, Thorlabs), a Powell lens (PL, fan angle = 10°, Laserline optics Canada), two cylindrical lenses (CL, f = 75 mm. LJ1703RM-A, Thorlabs). The schematic of both setups is shown in Figure 1. A more detailed description of the optical arrangement and characterisation of the light-sheet imaging performance is available (Battistella et al., 2022 (link)).

The 0.8 mm diameter laser beam was expanded to a diameter of 8 mm using a home-made telescope (f = 25 mm LA1951-A Thorlabs, f = 250 mm LA1461-A Thorlabs) and then directed through a cylindrical lens (f = 300 mm LJ1558RM-A, Thorlabs) to form a static Gaussian light-sheet at the specimen plane of the Mesolens approximately 300 mm from the cylindrical element. The cylindrical lens was mounted on a vertical breadboard by means of an optical cage system to precisely position it at the height of the Mesolens focal plane. To generate a 3 mm-long light-sheet (which corresponds to the FOV of the Mesolens) and considering a 488 nm wavelength, from Equations (1) and (2) the theoretically calculated minimum beam thickness is 30 μm, with a thickness of 42 μm at the edges of the FOV.