Aspheric lens structures and fabrication methods thereof
Aspheric lens structures with dual aspheric surfaces and fabrication methods thereof are disclosed. An aspheric lens structure includes a first lens component with an aspheric top surface disposed on a second lens component, wherein the interface between the first lens component and the second lens component is spherical. The second lens component includes an aspheric back surface, wherein the radius of curvature of the aspheric top surface of the first lens component is different than the radius of curvature of the aspheric back surface of the second lens component. The second lens component may also include a planar back surface with a third lens component disposed on the planar back surface of the second component. The third lens component includes an aspheric back surface, wherein the radius of curvature of the aspheric top surface of the first lens component is different than the radius of curvature of the aspheric back surface of the third lens component.
1. An aspheric lens structure, comprising:
a first lens component with an aspheric top surface disposed on a second lens component, wherein the interface between the first lens component and the second lens component is spherical;
a substrate configured as a carrier on which the aspheric lens structure is formed,
the substrate carrying an array of the aspheric lens structures; and a layer of black dye disposed on the substrate as a buffer of the aspheric lens structure.
2. The aspheric lens structure according to claim 1 , wherein the second lens component comprises a spherical back surface.
3. The aspheric lens structure according to claim 1 , wherein the second lens component comprises an aspheric back surface.
4. The aspheric lens structure according to claim 3 , wherein the radius of curvature of the aspheric top surface of the first lens component is different than the radius of curvature of the aspheric back surface of the second lens component.
5. The aspheric lens structure according to claim 1 , wherein the second lens component comprises a planar back surface and a third lens component is disposed on the planar back surface of the second component.
6. The aspheric lens structure according to claim 5 , wherein the third lens component comprises an aspheric back surface.
7. The aspheric lens structure according to claim 6 , wherein the radius of curvature of the aspheric top surface of the first lens component is different than the radius of curvature of the aspheric back surface of the third lens component.
8. A method for fabricating an aspheric lens structure, comprising:
providing a substrate;
perforating a hole through the substrate;
inserting a ball lens in the hole exposing a pre-curvature of the ball lens;
applying a layer of black dye on the substrate to obstruct an unnecessary part of the ball lens;
conformably forming a photoresist layer on the substrate and the exposed ball lens; and
forming the photoresist layer by lithography to create an aspheric surface of the photoresist layer on the ball lens configured as a first lens component.
9. The method for fabricating an aspheric lens structure according to claim 8 , further comprising:
polishing back of the ball lens to create a planar back surface configured as a second lens component; and
forming a third lens component with an aspheric back surface on the planar back surface of the second component.
10. The method for fabricating an aspheric lens structure according to claim 9 , wherein the third lens component is formed by molding.
11. The method for fabricating an aspheric lens structure according to claim 9 , wherein the radius of curvature of the aspheric top surface of the first lens component is different than the radius of curvature of the aspheric back surface of the third lens component.
12. The method for fabricating an aspheric lens structure according to claim 9 , wherein the radius of curvature of the aspheric top surface of the first lens component is different than the radius of curvature of the aspheric back surface of the third lens component.
13. The method for fabricating an aspheric lens structure according to claim 8 , further comprising:
removing the ball lens creating a cavity; and
forming a second lens component with an aspheric back surface in the cavity.
14. The method for fabricating an aspheric lens structure according to claim 13 , wherein the second lens component is formed by molding.
15. The method for fabricating an aspheric lens structure according to claim 8 , wherein the step of forming the photoresist layer by lithography is performed by a phase transition mask lithography.
16. The method for fabricating an aspheric lens structure according to claim 8 , further comprising a step of reflowing to change the curvature of the aspheric surface of the photoresist layer.
17. The method for fabricating an aspheric lens structure according to claim 8 , further comprising a step of molding to change the curvature of the aspheric surface of the photoresist layer.