Light Sheet Microscopy Calculator
Gaussian light sheet thickness, Rayleigh range and field of view, and the effective axial resolution of LSFM/SPIM.
Results
Thickness and field of view vs illumination NA
Sheet profile along the beam
Model
w₀ = λ_ex/(π NA_ill), z_R = π n w₀²/λ_ex, w(x) = w₀ √(1 + (x/z_R)²)
Sheet FWHM = √(2 ln 2) w₀; detection axial FWHM = 0.88 λ_em/(n − √(n² − NA_det²))
Effective axial FWHM = (1/FWHM_sheet² + 1/FWHM_det²)^(−1/2)
Lateral FWHM = 0.51 λ_em/NA_det (Airy)
A Gaussian sheet from a cylindrical lens, in the paraxial limit (NA_ill ≲ 0.3). The detected axial profile is the product of the sheet and the detection PSF; treating both as Gaussians gives the reciprocal quadrature sum (Engelbrecht and Stelzer 2006). A thinner sheet improves sectioning but shortens the field of view as NA_ill⁻²: at ±z_R the sheet is √2 thicker. Bessel, lattice and tiled sheets escape this trade-off and are not modelled. Selective plane illumination microscopy (SPIM) is the same geometry.
Model and references
Textbook approximation. A standard approximation from the literature (for example paraxial, plane-wave or Gaussian-beam), valid within the range the page states. About the tiers
Paraxial Gaussian sheet from a cylindrical lens (NA_ill ≤ 0.3, the 1/e² half-angle). The effective axial FWHM combines the sheet and the scalar detection PSF as Gaussians; Bessel and lattice sheets are not modelled.
- Engelbrecht C. J., Stelzer E. H. K. (2006). Resolution enhancement in a light-sheet-based microscope (SPIM). Opt. Lett. 31, 1477–1479. Axial resolution of sheet × detection PSF. doi:10.1364/OL.31.001477
- Huisken J., Swoger J., Del Bene F., Wittbrodt J., Stelzer E. H. K. (2004). Optical sectioning deep inside live embryos by selective plane illumination microscopy. Science 305, 1007–1009. doi:10.1126/science.1100035
- Siegman A. E. (1986). Lasers, ch. 17. University Science Books. Gaussian beam waist, Rayleigh range and divergence.