Patent ID: 7830617

Claim:
An optical component comprising: at least a first aspherical refractive surface, wherein the first aspherical refractive surface constitute a part of a boundary between a first medium having a refractive index n 1 and a second medium having a refractive index n 2 , a first curve is defined as a collection of intersections between the x-z plane of a rectangular coordinate system and the first aspherical refractive surface, wherein the origin of the rectangular coordinate system is located within the second medium, and the z-axis of the rectangular coordinate system passes through the origin and a point on the first aspherical refractive surface, the said first curve is symmetric about the z-axis, a distance from the origin to a first point on the first curve with a zenith angle θ is r(θ), rectangular coordinates (x, z) and polar coordinates (θ, r) of the first point in the x-z plane satisfy relations given in Eqs. 1 and 2, x (θ)= r (θ)sin θ (Eq. 1) z (θ)= r (θ)cos θ (Eq. 2) the distance r(θ) is given as Eq. 3, r ⁡ ( θ ) = r ⁡ ( θ i ) ⁢ exp ⁡ [ ∫ θ i θ ⁢ - n 1 ⁢ sin ⁡ ( δ - θ ′ ) n 1 ⁢ cos ⁡ ( δ - θ ′ ) - n 2 ⁢ ⅆ θ ′ ] ( Eq . ⁢ 3 ) said θ i is a zenith angle of a second point on the first curve, said r(θ i ) is a corresponding distance from the origin to the second point, said δ is an arbitrary function of the zenith angle θ of the first point (δ=δ(θ)), and the zenith angle θ ranges from a minimum θ 1 not smaller than zero to a maximum θ 2 smaller than π/2.