Multifocal lens

A method for producing a multifocal lens (1) having several concentric diffractive zones (7, 8, 9, 10) on a surface (2) of the lens, wherein the method comprises:

• mathematically providing a diffraction phase structure for each diffractive zone (7, 8, 9, 10) by providing for each diffractive zone (7, 8, 9, 10) following piecewise function, which comprises three phase terms:
• ϕ
• ⁡
• (
• ξ
• )
• =
• 2
• ⁢
• π
• ×
• {
• p
• 1
• ⁢
• ξ
• ,
• 0
• ≤
• ξ
• <
• w
• 1
• p
• 2
• ⁢
• ξ
• +
• q
• 2
• ,
• w
• 1
• ≤
• ξ
• <
• w
• 2
• p
• 3
• ⁢
• ξ
• +
• q
• 3
• ,
• w
• 2
• ≤
• ξ
• <
• 1
• ,
• wherein ξ indicates a position within the respective diffractive zone (7, 8, 9, 10) in a radial direction, φ(ξ) indicates a phase shift experienced by light passing through the position indicated by ξ, w1 and w2 define a spatial partitioning of the respective diffractive zone (7, 8, 9, 10) in the radial direction in accordance with the three phase terms, p1, p2 and p3 indicate gradients of the three phase terms and q2 and q3 are constants, wherein ξ depends quadratically on a radial distance to the center of the surface (2) of the lens (1) and is normalized with respect to the radial width of the respective diffractive zone (7, 8, 9, 10), and wherein the gradients p1, p2 and p3 are negative;
• and
• forming the diffractive multifocal lens (1) such that the diffractive zones (7, 8, 9, 10) have the mathematically provided diffraction phase structures.

A multifocal lens (1) having several concentric diffractive zones (7, 8, 9, 10) on a surface (2) of the lens, wherein in each diffractive zone (7, 8, 9, 10) a diffraction phase structure is defined, which diffraction phase structure is expressible by a smoothed version of the following piecewise function, which comprises three phase terms:

• ϕ
• ⁡
• (
• ξ
• )
• =
• 2
• ⁢
• π
• ×
• {
• p
• 1
• ⁢
• ξ
• ,
• 0
• ≤
• ξ
• <
• w
• 1
• p
• 2
• ⁢
• ξ
• +
• q
• 2
• ,
• w
• 1
• ≤
• ξ
• <
• w
• 2
• p
• 3
• ⁢
• ξ
• +
• q
• 3
• ,
• w
• 2
• ≤
• ξ
• <
• 1
• ,
• wherein ξ indicates a position within the respective diffractive zone (7, 8, 9, 10) in a radial direction, φ(ξ) indicates a phase shift experienced by light passing through the position indicated by ξ, w1 and w2 define a spatial partitioning of the respective diffractive zone (7, 8, 9, 10) in the radial direction in accordance with the three phase terms, p1, p2 and p3 indicate gradients of the three phase terms and q2 and q3 are constants, wherein ξ depends quadratically on a radial distance to the center of the surface (2) of the lens (1) and is normalized with respect to the radial width of the respective diffractive zone (7, 8, 9, 10), and wherein the gradients p1, p2 and p3 are negative.

A method for producing a multifocal lens (1) having several concentric diffractive zones (7, 8, 9, 10) on a surface (2) of the lens, wherein the method comprises:

• mathematically providing a diffraction phase structure for each diffractive zone (7, 8, 9, 10) by providing for each diffractive zone (7, 8, 9, 10) a smoothed version of following piecewise function, which comprises three phase terms:
• ϕ
• ⁡
• (
• ξ
• )
• =
• 2
• ⁢
• π
• ×
• {
• p
• 1
• ⁢
• ξ
• ,
• 0
• ≤
• ξ
• <
• w
• 1
• p
• 2
• ⁢
• ξ
• +
• q
• 2
• ,
• w
• 1
• ≤
• ξ
• <
• w
• 2
• p
• 3
• ⁢
• ξ
• +
• q
• 3
• ,
• w
• 2
• ≤
• ξ
• <
• 1
• ,
• wherein ξ indicates a position within the respective diffractive zone (7, 8, 9, 10) in a radial direction, φ(ξ) indicates a phase shift experienced by light passing through the position indicated by ξ, w1 and w2 define a spatial partitioning of the respective diffractive zone (7, 8, 9, 10) in the radial direction in accordance with the three phase terms, p1, p2 and p3 indicate gradients of the three phase terms and q2 and q3 are constants, wherein ξ depends quadratically on a radial distance to the center of the surface (2) of the lens (1) and is normalized with respect to the radial width of the respective diffractive zone (7, 8, 9, 10), and wherein the gradients p1, p2 and p3 are negative;
• and
• forming the diffractive multifocal lens (1) such that the diffractive zones (7, 8, 9, 10) have the mathematically provided diffraction phase structures.