Wafer scale production of optical elements
View Patent ↗Improved optical element wafers comprising stacked, optically coupled etalon wafers are disclosed. Each etalon wafer comprises a bulk optic wafer defining the optic cavity between selectively transparent thin film mirror coatings. The bulk optic wafer comprises an optically transparent body, such as a portion of a substrate wafer, along with a wedge correcting coating on at least one of the two surfaces of the optically transparent body and/or a thickness-adjustment layer on one or both surfaces. The bulk optic wafer is a solid, self-supporting body, optically transparent (at the wavelength or wavelengths of interest), whose thickness, i.e., the dimension between the selectively transparent surfaces, defines the cavity spacing of the bulk optic etalon wafer. Methods of making and using the optical element wafers are also disclosed.
1. An optical element wafer comprising stacked, optically matched and optically coupled etalon wafers, at least one of the optically coupled etalon wafers comprising first and second selectively transparent thin film mirror coatings on opposite first and second surfaces, respectively, of a bulk optic wafer having a diameter of at least 1 inch, the bulk optic wafer comprising an optically transparent body and the bulk optic wafer defining the cavity spacing of the etalon wafer, wherein the bulk optic wafer further comprises a wedge coating overlying the optically transparent body.
2. The optical element wafer of claim 1 , wherein the wedge coating and the optically transparent body are formed of substantially the same material.
3. The optical element wafer of claim 1 , wherein the wedge coating is formed of material comprising a similar refractive index as material comprising the optically transparent body.
4. The optical element wafer of claim 3 , wherein differences in refractive index of the material comprising the wedge coating and the material comprising the optically transparent body is less than about ±0.01.
5. The optical element wafer of claim 1 , wherein the wedge coating at its thickest point has a thickness of less than about 100 nm.
6. The optical element wafer of claim 1 , wherein the bulk optic wafer further comprises a thickness-adjustment layer overlying the optically transparent body.
7. The optical element wafer of claim 6 , wherein the thickness-adjustment layer has a substantially uniform thickness greater than 0 and less than 100 microns.
8. The optical element wafer of claim 6 , wherein the thickness-adjustment layer and the optically transparent body are formed of substantially the same material.
9. The optical element wafer of claim 6 , wherein the thickness-adjustment layer is formed of material comprising a similar refractive index as material comprising the optically transparent body.
10. The optical element wafer of claim 9 , wherein differences in refractive index of the material comprising the thickness-adjustment layer and the material comprising the optically transparent body is less than about ±0.01.
11. An optical element wafer comprising stacked, optically matched and optically coupled etalon wafers, at least one of the optically coupled etalon wafers comprising first and second selectively transparent thin film mirror coatings on opposite first and second surfaces, respectively, of a bulk optic wafer having a diameter of at least 1 inch, the bulk optic wafer comprising an optically transparent body and the bulk optic wafer defining the cavity spacing of the etalon wafer, wherein each of the optically coupled etalon wafers is spaced from an adjacent one of the optically coupled etalon wafers a distance equal to an odd number of QWOTs.
12. An optical element wafer comprising stacked, optically matched and optically coupled etalon wafers, at least one of the optically coupled etalon wafers comprising first and second selectively transparent thin film mirror coatings on opposite first and second surfaces, respectively, of a bulk optic wafer having a diameter of at least 1 inch, the bulk optic wafer comprising an optically transparent body and the bulk optic wafer defining the cavity spacing of the etalon wafer, wherein each of the optically coupled etalon wafers is spaced from an adjacent one of the optically coupled etalon wafers a distance equal to substantially zero QWOTs.
13. An optical element wafer comprising stacked, optically matched and optically coupled etalon wafers, at least one of the optically coupled etalon wafers comprising first and second selectively transparent thin film mirror coatings on opposite first and second surfaces, respectively, of a bulk optic wafer having a diameter of at least 1 inch, the bulk optic wafer comprising an optically transparent body and the bulk optic wafer defining the cavity spacing of the etalon wafer, further comprising a bonding layer attaching a first etalon wafer of the optically coupled etalon wafers to an adjacent etalon wafer.
14. The optical element wafer of claim 13 , wherein the bonding layer is in an optical path through the optically coupled etalon wafers and optically couples the first etalon wafer to the adjacent etalon wafer.
15. The optical element wafer of claim 13 , wherein the bonding layer is substantially out of an optical path through the optically coupled etalons.
16. The optical element wafer of claim 13 , wherein the bonding layer comprises a material selected from the group consisting of adhesives, epoxies, and fritted glass.
17. The optical element wafer of claim 13 , wherein the bonding layer comprises spacer beads in an adhesive, a mono-layer of the spacer beads establishing the adhesive thickness between the first etalon wafer and the adjacent etalon wafer.
18. The optical element wafer of claim 13 , wherein the bonding layer comprises fritted glass.
19. An optical element wafer comprising stacked, optically matched and optically coupled etalon wafers, at least one of the optically coupled etalon wafers comprising first and second selectively transparent thin film mirror coatings on opposite first and second surfaces, respectively, of a bulk optic wafer having a diameter of at least 1 inch, the bulk optic wafer comprising an optically transparent body and the bulk optic wafer defining the cavity spacing of the etalon wafer, wherein a first etalon wafer of the optically coupled etalon wafers is attached to, and spaced from, an adjacent etalon wafer by stand-offs.
20. The optical element wafer of claim 19 , wherein the stand-offs are not in an optical path through the optically coupled etalons.
21. The optical element wafer of claim 20 , wherein the stand-offs are formed of fritted glass.