RAPID PROTOTYPING OF OPTICAL COMPONENTS, PARTICULARLY LENSES, FOR PRODUCING CUSTOMIZED OPTICAL SURFACE SHAPES

Abstract

The present invention relates to a method for producing at least one optical component (1), comprising the steps of: a) Providing at least one cavity (2), wherein the at least one cavity (2) is delimited on a first side by a surface (3a) of a first membrane portion (3), wherein a shape of the first membrane portion (3) is adjustable; b) Filling a material (4) into the at least one cavity (2) for forming at least one optical component (1), such that the material (4) contacts a surface (3a) of the first membrane portion (3); c) Adjusting the shape of the first membrane portion (3); d) Curing the material (4) filled into the at least one cavity (2) so that the material (4) forms a first interface (e.g. a first optical surface) (1a) of the at least one optical component (1), which first interface (1a) comprises a shape defined by a shape of the surface (3a) of the first membrane portion (3).

Claims

1. A method for producing at least one optical component (1), comprising the steps of: a1) providing at least one cavity (2) b1) filling a liquid material (4) into the at least one cavity (2) c1) adjusting a shape of a first surface (4a) of the liquid material (4), d1) curing the liquid material (4) filled into the at least one cavity (2) so that the liquid material (4) becomes a rigid material (40) and the first surface (4a) becomes a first interface (40a), wherein a shape of the first interface (40a) is defined by the shape of the first surface (4a), and either e1) forming the at least one optical component by means of a molding process, wherein the first interface (40a) provides at least one surface of a molding tool and the shape of an optical surface of the optical component (1) is formed by means of the first interface (40a), or e2) the optical component comprises the rigid material (40) and the first interface (40a) is an optical surface of the optical component (1).

2. The method according to claim 1, wherein in method step a1) the at least one cavity (2) is delimited on a first side by a surface (3a) of a first membrane portion (3), wherein a shape of the first membrane portion (3) is adjustable; in method step b1) the liquid material (4) is filled into the at least one cavity (2), such that the liquid material (4) contacts the surface (3a) of the first membrane portion (3); in method step c1) the shape of the first surface (4a) of the liquid material is adjusted by adjusting the shape of the first membrane portion (3).

3. The method according to claim 1 or 2, wherein the at least one optical component (1) is a lens and the optical surface is a refractive surface of the lens.

4. The method according to one of the claims 1 to 3, wherein the at least one cavity (2) is formed by an opening (5a) formed in a mask (5), wherein the first membrane portion (3) is connected to the mask (5) and covers said opening (5a) so as to delimit the at least one cavity (2) on said first side.

5. The method according to claim 4, wherein the mask (5) comprises at least one channel (7) through which the at least one cavity (2) is filled with the liquid material (4).

6. The method according to claim 4 or 5, wherein after method step d1) the mask (3) carries the rigid material (40).

7. The method according to one of the preceding claims, wherein the method comprises the method step e1), wherein adhesion of the optical component to the first interface (40a) is reduced by means of a coating applied onto the first interface (40a) or the membrane (3) which is arranged between the first interface (40a) and the optical component (1) or a nano-structure formed by means of the first interface (40a).

8. The method according to one of the preceding claims 1 through 6, wherein the method comprises method step e2), wherein reflection of light in the visible wavelength range at the first interface (40a) is reduced by means of a coating applied onto the first interface (40a) or the membrane (3) or a nano-structure formed by means of the first interface.

9. The method according to one of the claims 4 to 8, wherein the method comprises method step e2), and an optical element (11) is provided on a side of the mask (5) that faces away from the first surface (4a).

10. The method according to claim 9, wherein the optical element (11) comprises a refractive index that is essentially equal to the refractive index of the rigid material (40), and/or wherein the optical element (11) comprises the same material as the rigid material (40).

11. The method according to claim 9 or 10, wherein the optical element (11) is bonded to the rigid material (40) in method step d1).

12. The method according to one of the claims 9 to 11, wherein the optical element (11) comprises a curved optical surface (11a), and the curved optical surface (11a) faces away from the rigid material (40) filled into the at least one cavity (2).

13. The method according to one of the claims 1 to 8, wherein the method comprises method step e2), and wherein the at least one cavity (2) is delimited on a second side opposing said first side by a surface (6a) of a second membrane portion (6), wherein a shape of the second membrane portion (6) is adjustable, wherein step b1) further comprises filling the liquid material (4) into the at least one cavity (2), so that the liquid material (4) also contacts the surface (6a) of the second membrane portion (6), wherein step c1) further comprises adjusting the shape of the second membrane portion (6), wherein step d1) further comprises curing the liquid material (4) filled into the at least one cavity (2) so that the liquid material forms a second interface (40b) of the at least one optical component (1), which second interface (40b) comprises a shape defined by a shape of the surface (6a) of the second membrane portion (6).

14. The method according to one of the preceding claims, wherein the method comprises method step e2), the step a1) further comprises providing a carrier (9), particularly for carrying the at least one optical component (1), and. the method step d1) further comprises removing the carrier (9) from the rigid material (40), or the carrier (9) is fixedly attached to the rigid material (40) and the carrier (90) forms a mount for the at least one optical component (1).

15. The method according to claim 14, wherein the carrier (9) is a printed circuit board.

16. The method according to one of the claim 14 or 15, wherein the carrier (9) comprises at least one opening (9a), wherein the liquid material (4) is also filled into the at least one opening (9a) of the carrier (9) for connecting the at least one optical component (1) in a form-fitting manner to the carrier (9) in method step d1).

17. The method according to claim 16, wherein the at least one opening (9a) of the carrier (9) forms an aperture of the at least one optical component (1).

18. The method according to claim 14 or 16, wherein the carrier (9) is a transparent carrier comprising a first side (91) facing the liquid material (4) which is filled into the cavity in method step b1) and a second side (92) facing away from the first side of the carrier (9), wherein the carrier (9) separates the at least one cavity (2) into a first region (2a) extending away from the carrier (9) starting from the first side (91) and a second region (2b) extending away from the carrier (9) starting from the second side (92), wherein step b1) further comprises filling the liquid material (4) into the at least one cavity (2) so that the liquid material (4) contacts the first side (91) of the carrier (9), and wherein step d1) further comprises curing the liquid material (4) in the first region (2a) so that the rigid material (40) is bonded to the first side (91) of the carrier (9).

19. The method according to claim 18, wherein the method comprises the further steps of: b2) filling the liquid material (4) into the second region (2b) of the at least one cavity (2) so that the liquid material contacts the second side (92) of the carrier (9); c2) adjusting the shape of a second surface (4b) of the liquid material (4) in the second region (2b); d2) curing the liquid material (4) filled into the second region (2b) so that the liquid material (4) becomes a rigid material (40) and the second surface (4b) becomes a second interface (40b), wherein a shape of the second interface (40b) is defined by the shape of the second surface (4b), and so that the rigid material (4) is bonded to the second side (92) of the carrier (9), wherein method steps b2), c2) and d2) are performed after method step d1) in the order listed.

20. The method according to one of the preceding claims, wherein method step c1) and/or method step c2) comprises at least one of: deforming the mask (5); applying pressure to the mask (5) in several spots of the mask simultaneously; adjusting a pressure (P1) of the liquid material (4) and/or an ambient pressure (P2, P3) outside the at least one cavity (2); sucking or pressing the first membrane portion (3) into a molding tool and/or sucking or pressing the second membrane portion (6) into a molding tool; pushing a master against the first membrane portion (3) and/or pushing a master against the second membrane portion (6); changing a distance between a first and a second part (51, 52) of the mask (5); changing a distance between the first membrane portion (3) and the second membrane portion (6); rotating the liquid material so that the shape of the first (4a) and/or second (4b) surface is at least partially defined by a centrifugal force applied to the liquid material (4).

21. The method according to one of the preceding claims, wherein in method step c1), c2), d1) and/or d2) a shape of the first (4a) and/or second (4b) surface is measured.

22. The method according to one of the preceding claims, wherein the shape of the first surface (4a) and/or the second surface (4b) is adjusted iteratively.

23. The method according to one of the preceding claims, wherein in method step d1) and or method step d2) the liquid material (4) is irradiated with UV light (8) for curing.

24. The method according to one of the preceding claims, wherein in method step d1) and/or method step d2) sub regions of the liquid material (4) of the at least one optical component (1) are cured consecutively.

25. The method according to one of the claims 1 to 22, wherein in method step d1) and/or d2) the liquid material (4) is heated for curing.

26. The method according to one of the claims 4 to 25, wherein the mask (5) is removed after curing of the liquid material (4) of the at least one optical component (1).

27. The method according to one of the preceding claims, wherein in method step a1) a plurality of cavities (2) is provided, in method step b1) the plurality of cavities (2) is filled with the liquid material (4), wherein for each of the plurality of cavities (2) the liquid material (4) forms a first surface (4a) respectively; in method step c1) the shape of the first surfaces (4a) is adjusted; and in step d1) the liquid material (4) is cured so that the liquid material (4) becomes a rigid material (40) and the first surfaces (4a) become the first interfaces (40a), wherein a shape of the first interfaces (40a) is defined by the shape of the first surfaces (4a) respectively.

28. The method according to one of the claim 27 or 28, wherein the optical component (1) is a lens array comprising a plurality of lenses, wherein each first interface (40a) defines the shape of a refractive surface of the lenses respectively.

29. The method according to claim 29, wherein excess material, particularly uncured liquid material (4), between adjacent lenses is removed after curing of the liquid material (4).

30. The method according to claim 30, wherein in a method step f1) the lenses of the lens array are separated by means of at least one of: milling, laser cutting, stamping, cutting, punching, wherein the method step f1) is performed after method step d1).

31. The method according to one of the preceding claims comprising the method step e2), wherein after method step d1), in a method step b2) an additional liquid material is filled into the at least one cavity, wherein the additional liquid is adjacent to the interface fabricated the preceding method step d1) or d2), in a method step c2) a shape of an additional surface (4c) is adjusted, wherein the additional surface (4c) is arranged on a side of the additional liquid material opposing the interface (40a) which was fabricated in the preceding method step d1) or d2), and in a method step d2) the additional liquid material is cured so that the additional liquid material becomes an additional rigid material and the additional surface (4c) becomes the additional interface (40c), wherein a shape of the additional interface (40c) is defined by the shape of the additional surface (4c).

32. An optical device comprising at least one optical component (1) produced with the method according to one of the preceding claims.

33. An optical device, comprising: a rigid material (40), a component embedded at least partially in the rigid material (40), wherein the optical device comprises at least one optical surface (1a, 1b) configured to influence an interaction of light with said component in a pre-defined manner, wherein the at least one optical surface (1a, 1b) is formed by one of: the rigid material (40), a layer arranged on the rigid material (40), a membrane portion arranged on the rigid material (40).

34. The optical device according to claim 33, wherein the component is completely embedded in the rigid material (4).

35. The optical device according to claim 43 or 44, wherein the embedded component is one of: an electronic component; an optical component, a diffraction grating, an optical aperture, a filter, an optoelectronic component, a piece of jewelry, a sensor, a light source.

36. The optical device according to one of the claims 43 to 45, wherein the at least one optical surface (1a, 1b) is formed in a liquid state of the rigid material (4).

37. A device (100) for producing at least one optical component (1), comprising: at least one cavity (2) for receiving a liquid curable material (4), an actuator unit for defining a shape of a first surface (4a) of the liquid curable material (4) in the cavity (2), and a curing unit (102) for curing the liquid material (4), while the liquid material is in the at least on cavity (2).

38. A device (100) according to the preceding claim comprising a mask (5) with an opening (5a), a first membrane portion (3) being connected to the mask (5) and covering the opening (5a) to delimit said at least one cavity (2) at least on a first side, wherein the first membrane portion (3) comprises a surface (3a) for defining a shape of a first interface (1a) of the at least one optical component (1) to be produced, when the liquid material (4) is filled into the at least one cavity (2) and contacts said surface (3a) of the first membrane portion (3), an actuator unit (101) configured to adjust the shape of the first membrane portion (3) to adjust the shape of the interface (1a) of the at least one optical component (1), and a curing unit (102) for curing the liquid material (4), when the latter has been filled into the at least on cavity (2).

Description

[0171] Further features and advantages of the present inventions as well as embodiments of the present invention shall be described in the following with reference to the Figures, wherein

[0172] FIG. 1 shows a schematical illustration of an embodiment of the method according to the present invention for producing an optical component having a customized optical surface;

[0173] FIG. 2 shows an embodiment of adjusting the membrane portion for shaping the optical surface;

[0174] FIG. 3 shows a further embodiment of the method according to the present invention using a mask having a channel for applying the liquid material for forming the optical component(s);

[0175] FIG. 4 shows a further embodiment of the method according to the present invention using a carrier for delimiting the cavities used for forming the optical components in a two-step curing process;

[0176] FIG. 5 shows a further embodiment of the method according to the present invention using an optical element to which the rigid material is bonded upon curing;

[0177] FIG. 6 shows a further embodiment of the method according to the present invention using an optical element to which the rigid material is bonded upon curing;

[0178] FIG. 7 shows a further embodiment of the method according to the present invention, wherein the optical surfaces of the optical components are shaped by adjusting a pressure P1 of the liquid material in relation to an ambient pressure P2, P3;

[0179] FIG. 8 shows a further embodiment of the method according to the present invention, wherein the optical surfaces of the optical components are shaped with help of shaping liquids L1, L2 affected by gravity;

[0180] FIG. 9 shows a further embodiment of the method according to the present invention using a carrier to which the rigid material is bonded upon curing, wherein the carrier forms an aperture of the optical component;

[0181] FIG. 10 shows a further embodiment of the method according to the present invention for producing an optical component forming a prism;

[0182] FIGS. 11-12 show a top view (FIG. 11) and a cross-sectional view of a device for conducting the method according the present invention;

[0183] FIG. 13 shows an exemplary embodiment of a method for producing at least one optical component in a schematic sectional view, wherein a shape of a first surface is defined by means of a piston;

[0184] FIGS. 14a and 14b show an exemplary embodiment of a method for producing at least one optical component in a schematic sectional view, wherein additional interfaces are fabricated;

[0185] FIG. 15 shows an exemplary embodiment of a method for producing at least one optical component in a schematic sectional view, wherein the shape of a first and/or second surface is measured by means of a measurement unit;

[0186] FIG. 16 shows an exemplary embodiment of a method for producing at least one optical component in a schematic sectional view, wherein a shape of a second surface is defined by means of an actuation unit 101.

[0187] FIG. 1 shows the general concept of the method according to the present invention. The method uses a cavity 2 that is delimited on one side by a first membrane portion 3. The first membrane portion 3 comprises a surface 3a that will be contacted by liquid material 4 that is filled into the cavity 2. With the material being in a liquid state, the membrane 3 is adjusted to form e.g. a convex lens surface. The liquid material 4 filled into the cavity 2 can then be cured by means of either heat 8 or UV light 8 depending on the liquid material 4. The optical component 1 then comprises an interface 1a, here in form of an optical surface 1a, that comprises a shape that corresponds to the shape of the surface 3a of the first membrane portion 3. Generally, the actual optical surface can be formed by the interface 1a, but may also be formed by a layer (e.g. coating) arranged on the interface 1a. Particularly, the first membrane portion 3 can remain on the cured material 4/interface 1a and may then form the actual optical surface. Also, here, the first membrane portion 3 may be further processed for forming an optical surface using the first membrane portion 3 as a basis.

[0188] Particularly, generally, the curable liquid material can be a UV curable polymer that is preferably transparent for visible light.

[0189] Particularly, the cavity 2 can be formed by an opening 5a formed into a mask 5 that forms a lateral wall 5b of the cavity 2 and therewith defines a lateral contour of the optical component 1 to be produced. The opening 5a is covered by the preferably flexible first membrane portion 3 to delimit the cavity 2 and retain the liquid/rigid material 4 in the cavity 2.

[0190] For adjusting the shape of the surface 3a and therewith of the optical surface 1a, forces 10 can be applied to the flexible mask 5, wherein said forces particularly extend along an optical axis that runs perpendicular to the mask 5. FIG. 2 shows an example where the optical surface 1a gets a convex shape by applying forces 10 on either side of the opening 5a of the mask 5. The forces can be different, e.g. to also form the optical component into a prism.

[0191] FIG. 3 shows a modification of the embodiment shown in FIGS. 1 and 2, wherein here the mask 5 comprises at least one channel 7 for filling the cavity 2 of the mask with the liquid material.

[0192] Particularly, the mask 5 can comprise a first and a second part 51, 52 that are stacked on top of one another and together form the at least one channel 7 in the stacked configuration of the parts 51, 52 shown in FIG. 3. However, the channel 7 can also be formed in other ways.

[0193] Again, the cavity 2 can be formed by an opening 5a of the mask 5, which opening 5a is here delimited on two opposing sides by a flexible first membrane portion 3 and a flexible second membrane portion 6

[0194] Using such a configuration of the mask 5 allows to generate an optical component 1 having two opposing optical surfaces 1a, 1b that can be shaped depending on the shape of the surface 3a, 6a of the respective membrane portion 3, 6 that is contacted by the liquid material 4 when the latter is filled through the at least one channel 7 into the cavity 2.

[0195] Once the surfaces 3a, 6a are shaped as desired, the liquid material in the cavity 2 can be cured to form the optical component 1 (here e.g. a bi-convex lens 1).

[0196] In FIGS. 1 to 3 only a single cavity 2 is shown. However, the method also comprises embodiments using multiple such cavities 2 arranged side by side so that multiple optical components 1 can be formed in parallel. Eventually, the optical components 1 can be separated from one another to form individual optical devices 1. Alternatively, the optical components 1 can also be maintained in the interconnected configuration form an optical device in form of an array of connected optical devices 1 such a lens array.

[0197] The production of such a lens array comprised of multiple optical components 1 in a two-step process is shown for example in FIG. 4.

[0198] Here, the mask 5 comprises multiple openings 5a, wherein each opening 5a frames a flexible first membrane portion 3. The first membrane portions 3 may extend continuously between the mask 5 and the cavities 2. Alternatively, each opening 5a may be sealed by means of a separate first membrane portion 3.

[0199] Particularly, the interconnected optical components 1 can be cured in two steps. In a first step the cavities 2 are delimited by means of the mask 5 and the membrane portions 3 on one side and by carrier 9 arranged opposite the mask 5 and membrane portions 3 as shown in the upper part of FIG. 4. After having shaped the surfaces 3a as desired, the interconnected cavities 2 are filled with the liquid material 4. Then, after a first curing step resulting in a first half of the final array of optical components 1, said cured half is flipped and the carrier 9 is removed. During a second step, the cured half now delimits the cavities 2 instead of the carrier. The cavities 2 being delimited by the cured half of the array of optical components 1 and a mask 5 with membrane portions 3 are filled in turn with the liquid material 4 which then bonds to the already cured half upon curing of the material 4. This results in an array of optical components 1, here in the form of bi-convex lenses. However, arrays of other optical components 1 can be formed in this fashion as well.

[0200] FIG. 5 shows another variant of the method according to the present invention. Here an e.g. blank optical element 11 which delimits the cavity (or cavities) 2 on a side opposing the first membrane portion 3. The optical element 11 is being bonded to the rigid material 4 during curing. In particular, the rigid material 4 and the optical element 11 may have the same refractive index. Further, optical element 11 may have a concave or convex surface 11a facing away from the rigid material 4.

[0201] In particular, after curing the liquid material 4, the thickness along a z-direction of the rigid material 40 is smaller than the thickness along a z-direction of the optical element. For example, the optical element is selected such, that a deviation between the shape of the first surface 4a and the surface of the optical element 11 facing the rigid material 40 is minimized. In particular, the rigid material 40 has a non-uniform thickness, wherein the thickness is measured along the z-direction. For example, the minimal thickness of the rigid material along the z-direction is at most 0.5 mm, preferably at most 0.1 mm, highly preferred at most 0.05 mm.

[0202] According to yet another embodiment shown in FIG. 6, the mask 5 can be made of an opaque material. Thus, the mask 5 defines the contour of the portion of the liquid material, which is being cured by means of UV light 8 or heat 8 as indicated in FIG. 6.

[0203] FIG. 7 shows a further possibility of shaping the surfaces 3a, 6a of the membrane portions 3, 6 in order to shape the final optical surfaces 1a, 1b of the optical components 1 produced with the method. Particularly, the embodiment shown in FIG. 7 uses the configuration shown in FIG. 3 albeit with multiple interconnected cavities 2 that are arranged side by side in the lateral direction.

[0204] In order to adjust the shapes of the first and second membrane portion 3, 6 the pressure P1 of the liquid material 4 filled into the cavities 2 is adjusted such in relation to the ambient pressures P1, P2 on either side of the mask 5 that the shapes of the first and second membrane portions 3, 6 result in convex and concave optical components/lenses 1. However, depending on the pressures P1, P2, P3 also other surface shapes 1a, 1b can be easily generated.

[0205] Furthermore, FIG. 8 shows an embodiment, in which the shape of the first membrane portion(s) 3 is adjusted by means of two shaping liquids L1, L2. The ratio of the densities of the shaping liquids L1, L2 with respect to each other and with respect to the liquid material 4 as well as the level of the liquids L1, L2 is chosen such that a desired shape of the first membrane portion(s) result, as indicated in FIG. 8.

[0206] FIG. 9 shows yet another embodiment of the method according to the present invention. Here, a carrier 9 is arranged in the cavity 2. Particularly, the carrier 9 can be a printed circuit board (PCB). The carrier 9 comprises an opening 9a that is aligned with two opposing membrane portions 3, 6, i.e. first membrane portion 3 and second membrane portion 6, so that the opening 9a eventually forms an aperture of the optical component 1 to be produced.

[0207] Particularly, after having adjusted the shapes of the membrane portions 3, 6 as desired, the liquid material 4 is arranged in the opening 9a as well as above and below the carrier 9 (upper part of FIG. 9). For curing of the liquid material 4, the liquid material 4 is preferably exposed to the UV light 8 from both sides to avoid shadowing of the liquid material 4 by the carrier 9.

[0208] After the liquid material 4 is cured (middle part of FIG. 9), the mask 5 and non-cured liquid material 4 is removed. In particular, the membrane portions 3, 6 are removed. Due to the opening 9a being filled with the material 4, the optical component 1 can be connected to the carrier in a formfitting manner (cf. lower part of FIG. 9). In particular, the carrier 9 may comprise light emitting and/or detecting elements. The light emitting and/or detecting elements may be embedded by the cured material 4. In particular, the optical component 1 may be part of a gas sensor.

[0209] Furthermore, instead of providing an opening 9a, the carrier 9 may also be continuous but transparent. The carrier 9 then divides the cavity 2 into a first and a second region 2a, 2b. Here, the liquid material can be processed independently on either side of the carrier 2. For instance, after having adjusted the shape of the first membrane portion 3, liquid material 4 can be filled into the first region 2a of the cavity 2 between the first membrane portion 3 and the first side 91 of the carrier 9 and can then be cured to form the first optical surface 1a of the optical component 1. In another step, after having adjusted the shape of the second membrane portion 6, liquid material 4 can be filled into the second region 2b of the cavity 2 between the second membrane portion 6 and the second side 92 of the carrier 9 and can then be cured to form the second optical surface 1b of the optical component 1.

[0210] Using the method according to the present invention, also an optical component in form of a prism or comprising a prism can be generated as shown in FIG. 10.

[0211] Here, the first membrane portion 3 can also be made out of a stiff material. The tilt of the first membrane portion 3 can be adjusted by applying a force to the mask 5 and particularly by adjusting the pressure of the liquid material versus the environment. The liquid material may be cured by means of UV light 8 shining through the first membrane portion 3. In the framework of the present invention, the tilted position of the first membrane portion 3 is also considered to be a shape of the first membrane portion 3.

[0212] Particularly, the method according to the present invention can be performed by using a device 100 of the kind shown in FIGS. 11 and 12 in an exemplary fashion. This device 100 can be easily adapted to the individual embodiments a1 already described above.

[0213] Particularly, the device 100 comprises a mask 5 (see also above) which comprises at least one opening 5a with a first membrane portion 3 covering the opening 5a. The mask 5 and the first membrane portion 3 delimit a cavity 2 at least on one side. A filling unit is arranged to fill the cavity 2 with the liquid material 4.

[0214] Particularly, the device comprises an actuator unit 101 that can comprise multiple actuators 103, which can be arranged circumferentially around the first membrane portion 3. Particularly, the actuators 103 are configured to apply a force along the z-axis (e.g. optical axis) onto the mask 5. Thereby, the position of the mask 5 along the z-axis is adjusted. For example, the device 100 comprises at least four actuators 103, preferably at least eight actuators 103. Preferably, the actuators 103 are equidistantly spaced along the periphery of the first membrane portion 3 (or along the opening 5a). By adjusting the position of the mask 5 along the z-axis, the shape of the first membrane portion is adjusted which in turn determines the final shape of an optical surface 1a of an optical component 1 that is produced by the device 100 due to the fact that the liquid material 4 will contact the surface 3a of the first membrane portion 3 and will therefore assume the shape of the surface 3a of the first membrane portion 3.

[0215] Furthermore, the device preferably comprises a curing unit 102 such as a UV light for generating UV light 8 (or alternatively a heater for heating the liquid material 4). The curing unit 102 is arranged to cure the liquid material 4 as e.g. shown in FIG. 12, after the shape of the first membrane portion 3 has been adjusted by means of the actuators 103.

[0216] The method according to the present invention enables a cost-efficient and fast production of customized optical surfaces having a high optical quality.

[0217] FIG. 13 shows an exemplary embodiment of a method for producing at least one optical component in a schematic sectional view, wherein a shape of a first surface 4a is defined by means of a piston 71. The piston 71 and the first membrane portion 3 delimit the cavity 2, which is provided in method step a1), at two opposing sides. The mask 5 delimits the cavity 2 laterally.

[0218] In method step b1), the liquid material 4 may be filled into the cavity 2 through an injection port 72. The injection port 72 is integrally formed within the piston.

[0219] The first surface 4a of the liquid material 4 is adjacent to the first membrane portion. In method step c1) the shape of the first surface 4a of the liquid material 4 is adjusted by altering the pressure in the cavity 2. The pressure may be altered by moving the piston towards or away from the first membrane portion 3 and/or by filling more or less liquid material 4 into the cavity through the injection port 72.

[0220] In particular, the shape of the second surface 4b is defined by the shape of the piston 71. The piston 71 may comprise a rigid lens having a shape which forms a counterpart of the desired shape of the second surface 4b. In particular, the rigid lens of the piston 71 may be fabricated according to method steps a1), b1), c1), d1) and e1).

[0221] In method step d1), the liquid material 4 is cured so that the liquid material 4 becomes a rigid material 40 and the first surface 4a becomes a first interface 40a, wherein a shape of the first interface 40a is defined by the shape of the first surface 4a. The liquid material is cured by means of UV radiation 8, which is emitted by means of a curing unit 102, and which enters the cavity through the mask 5, which is transparent for UV radiation 8.

[0222] In a subsequent method step the at least one optical component may be formed by means of a molding process, wherein the first interface 40a provides at least one surface of a molding tool and the shape of an optical surface of the optical component 1 is formed by means of the first interface 40a.

[0223] Alternatively to method step e1), in a method step e2 the optical component comprises the rigid material 40 and the first interface 40a is an optical surface of the optical component 1.

[0224] FIGS. 14a and 14b show an exemplary embodiment of a method for producing at least one optical component in a schematic sectional view, wherein additional interfaces 4c are fabricated.

[0225] As shown in FIG. 14a, in method step a1) the cavity 2 is provided. The cavity 2 is delimited by the first membrane portion 3 and by the carrier 9 on opposing sides. In particular, the carrier 9 may be an on optical element 11, like a lens, having a curved surface. Alternatively, the carrier 9 may be a flat transparent carrier. The mask 5 delimits the cavity 2 laterally. The mask 5 comprises a bellows 53, which delimits the cavity laterally. The mask 5 may be moved along a z-direction, to adjust the shape of the first membrane portion 3. The mask 5, in particular the bellows 53, provides a flexible, and in particular liquid tight, connection between side wall 54 and the first membrane portion 3a.

[0226] The sidewall 54 surrounds the carrier 9 circumferentially in lateral directions (direction along the x-y-plane). The carrier is movable along the z-direction. In particular, the carrier is mounted on a positioning unit 93 which is arranged to move the carrier 9 along the z-axis. The position unknit may comprise a thread, which allows to adjust the position of the carrier 9.

[0227] In a method step b1) the liquid material 4 is filled into the cavity 2. In a method step c1), the shape of the first surface 4a of the liquid material 4 is adjusted. In this particular embodiment, the first surface 4a is concavely shaped. The shape may be adjusted by altering the relative pressure between cavity 2 and the region at a side opposed to the cavity with respect to the first membrane 3. Alternatively, the shape may be adjusted by moving the mask 5 along the z-direction. Moreover, the shape of the first membrane portion 3a may be adjusted by moving the carrier 9 along the z-direction.

[0228] In a method step d1) the liquid material 4 is cured, so that the liquid material 4 becomes a rigid material 40 and the first surface 4a becomes a first interface 40a, wherein the shape of the first interface 40a is defined by the shape of the first surface 4a.

[0229] After the method step d1), the position of the carrier 9 is adjusted along the z-direction, wherein the rigid material remains in contact with the carrier 9. Thus, an additional region 21 is generated in the cavity 2, which additional region 21 is delimited on one side by the first interface 40a.

[0230] As shown in FIG. 14b, in subsequent method steps b2), c2) and d2) an additional interface 40c is fabricated. As shown in FIG. 14b, in a method step b2) an additional liquid material 41 is filled into the at least one cavity, in particular in the additional region 21, wherein the additional liquid 41 is adjacent to the interface 40a fabricated the preceding method step d1). In particular, the additional liquid 41 may be adjacent to the additional interface 40c fabricated in a preceding method step d2), if multiple additional interfaces 40c are fabricated.

[0231] In a method step c2) a shape of an additional surface 4c of the additional liquid material is adjusted. The additional surface 4c is arranged on a side of the additional liquid material 41 opposing the interface 40a, 40c which was fabricated in the preceding method step d1) or d2). The shape of the additional surface may be adjusted by the same means as in method step c1).

[0232] In a method step d2), the additional liquid material is cured so that the additional liquid material 41 becomes an additional rigid material 410 and the additional surface 4c becomes the additional interface 40c, wherein a shape of the additional interface 40c is defined by the shape of the additional surface 4c.

[0233] After performing at least one iteration of the method steps b2), c2) and d2), the optical component comprises the rigid material 40 and the additional rigid material 410. The first interface 40a and the additional interface(s) 40c are optical surfaces of the optical component. In particular, the rigid material and the additional rigid material have different refractive indices. The (additional) rigid materials 40a, 40c which are arranged adjacent to one another have different refractive indices, whereby the additional interface(s) 40c form refractive interfaces. In particular, the optical component is an achromat or an apochromat.

[0234] FIG. 15 shows an exemplary embodiment of a method for producing at least one optical component in a schematic sectional view, wherein the shape of a first 4a and/or second 4b surface is measured by means of a measurement unit 120.

[0235] In a method step a1) the cavity 2 is provided, wherein the cavity is delimited by a first membrane portion 3 and a second membrane portion 6 on opposing sides of the cavity. The mask 5 delimits the cavity 2 laterally (along the X-Y-plane).

[0236] In a method step b1) the liquid material 4 is filled into the cavity 2 through a channel 7. The channel 7 connects the cavity 2 and a reservoir 55, which comprises the liquid material 4.

[0237] In a method step c1) a shape of the first surface 4a and the second surface 4b is adjusted. The shape of the first 4a and the second 4b surface is adjusted, by adjusting the relative pressure values between the cavity 2 and the regions adjacent to the first membrane portion 3 (pressure P2) and the second membrane portion 6 (pressure P3).

[0238] The channel 7 may remain open during method step c1), so that liquid material 4 may flow between the cavity 2 and the reservoir 55. In particular, the reservoir 55 and the cavity 55 are at the same pressure value P1. The reservoir 55 may be open, to be at ambient pressure. The ratio of P1 and P2 may be defined independently from the ratio of P1 and P3. The shape of the first surface may be controlled independently from the shape of the second surface by adjusting the pressure values P2 and P3, because the cavity 2 remains at a constant pressure value P1. Thus, a change in the shape of the first or second surface causes a flow of the liquid material through the channel 7. Advantageously, adjusting the shape of the first surface does not influence the shape of the second surface and vice versa.

[0239] The measurement unit is arranged to measure the shape of the first surface and the second surface by means of a measurement beam 123, which is transmitted through the first surface 4a and the second surface 4b. Alternatively, the measurement unit may be arranged to measure the shape of the first/second surface (4a, 4b) by means of reflection at the first and or second surface. In particular, the measurement unit 120 comprises a Shack Hartmann Sensor.

[0240] In a method step d1) the liquid material 4 is cured by means of UV radiation 8, so that the liquid material 4 becomes a rigid material 40 and the first surface 4a becomes a first interface 40a, and the second surface 4b becomes a second interface 40b. The UV radiation is directed towards the cavity by means of deflection mirrors 81, which may be transparent for the measurement beam. In particular, the measurement beam 120 and the UV-radiation 8 extend along a common optical path. FIG. 16 shows an exemplary embodiment of a method for producing at least one optical component in a schematic sectional view, wherein a shape of the second surface 4b is defined by means of an actuation unit 101. In particular, the actuation unit 101 is arranged to define a position along the z-axis of discrete points of the second surface 4b. The actuation unit 101 comprises multiple actuators 103, which are arranged to push against the second membrane portion 6. In particular, the actuators comprise pins which are in contact with the second membrane portion, wherein the position of the pins along the z-axis is adjustable. The actuators 103 for adjusting the position of the pins along the z-axis may be piezo actuators, voice coil actuators, electropermanent magnet actuators, stepper motors or hydraulic actuators.

[0241] The pressure P1 of the liquid material 4 remains constant during method step c1). In particular, the pressure P1 corresponds to ambient pressure. Thus, changing the shape of the second surface does not affect the shape of the first surface 4a. the shape of the first surface 4a is adjusted by adjusting the relative pressure between P1 and P2.