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docs:gaussian_beam [2017/12/01 17:45] Jon Daniels |
docs:gaussian_beam [2019/05/07 23:18] (current) Jon Daniels |
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| * NA_illum is the numerical aperture of the illumination | * NA_illum is the numerical aperture of the illumination | ||
| - | For Gaussian beams the beam/sheet extent or imaging field of view = k2 * lambda / NA_illum^2 where | + | For Gaussian beams the beam/sheet extent or imaging field of view = k2 * lambda |
| * k2 is a constant that depends on how you define the acceptable intensity variation across the field of view. Commonly k2 is taken to be 0.64, which corresponds to the two-sided field of view where the beam thickness as measured by the 1/e^2 criteria has increased by a factor of sqrt(2). | * k2 is a constant that depends on how you define the acceptable intensity variation across the field of view. Commonly k2 is taken to be 0.64, which corresponds to the two-sided field of view where the beam thickness as measured by the 1/e^2 criteria has increased by a factor of sqrt(2). | ||
| * lambda is the wavelength, in this case the excitation laser | * lambda is the wavelength, in this case the excitation laser | ||
| + | * n is the refractive index of the media (1.33 for water) | ||
| * NA_illum is the numerical aperture of the illumination | * NA_illum is the numerical aperture of the illumination | ||
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| For a typical diSPIM setup, NA_illum = 0.366 * iris_D / EFL where | For a typical diSPIM setup, NA_illum = 0.366 * iris_D / EFL where | ||
| * 0.366 is the half the total magnification between iris and back focal plane | * 0.366 is the half the total magnification between iris and back focal plane | ||
| - | * iris_D is the iris diameter | + | * iris_D is the iris diameter |
| * EFL is the effective focal length of the objective, e.g. 5mm for Nikon 40x, 9mm for Olympus 20x, and 12mm for the cleared tissue objective @ RI~1.45 | * EFL is the effective focal length of the objective, e.g. 5mm for Nikon 40x, 9mm for Olympus 20x, and 12mm for the cleared tissue objective @ RI~1.45 | ||
