Zone Plate Equations
Zone Plate Equations
Variables
- f = focal length
- λ = wavelength
- ρr = phase variation
- rm = radius of mth zone
- m = zone number
- 1 ≤ N ≤ ∞
Definitions
- GZP = Geometric Zone Plate, paraxial, f# > 10
- IZP = Interferometric Zone Plate, f# < 10
- GHZP = Generalized Holographic Zone Plate
Equations
- For GZP:
- For IZP:
- For GHZP:
Properties of Zone Plates
- (m = number of zones illuminated)
- Hybrid condition (f zone)/(f lens) = (n-1)/λ (dispers const.))
- Hybrid Achromats typically use GZP pattern and less than 300 zones
Last modified on 9/22/97