SOLS excitation

Uniform light-sheets

One way to choose a 'uniform' light-sheet is to keep the intensity above 90% for the length of the sample \(z_s\): \[ z_{90} \geq \frac{z_s}{2} \tag{1}\] where, \[ z_{90} = \frac{z_R}{3} \tag{2}\] and so we require: \[ z_R \geq \frac{3z_s}{2} \tag{3}\]

The beam waist is related to the Rayleigh range with: \[ w_0 = \sqrt{\frac{\lambda_0 z_R}{\pi n}} \tag{4}\] So for a given sample size we can find the transverse full width half max with: \[ w_{FWHM} = \sqrt{\frac{3 \ln 2 \lambda_0 z_s}{\pi n}} \tag{5}\] which we can readily plot over the sample ranges interest, for example 5-100um:

Note: This setup benefits from even illumination (ignoring absorption and scattering), but the light-sheets can be quite thick (e.g. 5um for 100um sample!). Thick light-sheets reduce sectioning and increase photodose for fine sampling.