Method of producing an optical device and a corresponding system
A method of producing an optical device from a volume of a curable composition, includes the following steps: —polymerizing a first portion of the volume by irradiating an external surface of the volume with a light irradiation, thereby increasing a transmittance of the first portion for the light irradiation; —polymerizing a second portion of the volume by irradiating the second portion with the light irradiation through the external surface and the polymerized first portion, wherein the light irradiation has a light intensity varying over the external surface between a first light intensity and a second light intensity distinct from the second light intensity. A corresponding system is also described.
1. A method of producing an optical device from a volume of a curable composition, comprising the following steps:
polymerizing a first portion of said volume by irradiating an external surface of said volume with a light irradiation, thereby increasing a transmittance of said first portion for said light irradiation;
polymerizing a second portion of said volume by irradiating said second portion with said light irradiation through said external surface and the polymerized first portion,
wherein said light irradiation has a light intensity varying over said external surface between a first light intensity and a second light intensity distinct from said first light intensity, and
wherein the step of polymerizing the first portion and the step of polymerizing the second portion are performed continuously from portion to portion of the curable composition to obtain a homogeneous transparent polymerized material.
2. The method of claim 1 , wherein said light intensity is varying over time for at least one point of said external surface.
3. The method of claim 1 , wherein said light irradiation is in the ultraviolet range.
4. The method of claim 1 , wherein said light irradiation is in the visible range.
5. The method of claim 1 , wherein said curable composition includes a photo-initiator sensitive to the light irradiation and having photobleaching properties.
6. The method of claim 5 , wherein said photo-initiator is a Bis Acyl Phosphine Oxide.
7. The method of claim 1 , wherein said curable composition contains an acrylate.
8. The method of claim 1 , comprising a step of degassing the curable composition prior to polymerizing said first portion.
9. The method of claim 1 , wherein said optical device is an optical lens.
10. The method of claim 1 , wherein said curable composition is in a container with a bottom part; wherein the optical device is formed by polymerization starting from the bottom part; and wherein said light irradiation is transmitted through said bottom part.
11. The method of claim 10 , wherein said bottom part has a convex shape facing said volume, whereby the produced optical device has a concave shape.
12. The method of claim 1 , wherein light intensity in a center of said external surface is greater than light intensity at a periphery of said external surface.
13. The method of claim 1 , wherein light intensity at a periphery of said external surface is greater than light intensity at a center of said external surface.
14. The method of claim 1 , wherein said light irradiation is produced by an emitter comprising a spatial light modulator.
15. The method of claim 2 , wherein said light irradiation is in the ultraviolet range.
16. The method of claim 2 , wherein said light irradiation is in the visible range.
17. The method of claim 2 , wherein said curable composition includes a photo-initiator sensitive to the light irradiation and having photobleaching properties.
18. The method of claim 3 , wherein said curable composition includes a photo-initiator sensitive to the light irradiation and having photobleaching properties.