Optical composites between similar and between dissimilar materials
Manufacturing techniques and composite structures that are able to meet increasing demanding requirements for large-scale crystal composites (e.g., greater than 100-200 mm in dimensions) that can be manufactured within reasonable time frames. A method of making an optical composite comprises providing first and second components to be bonded along respective surfaces, treating at least one component over at least a portion of the respective surface, and thereafter, bringing the first and second components into optical contact for bonding along the surface having the treated layer. Treating can include one or more of processing the component to provide a porous interface layer, processing the component to form a pattern of channels on the surface to be bonded, and providing an optical coating on the surface to be bonded.
1. An optical composite that comprises first and second components making optical contact across a porous interface layer derived from pretreatment of at least one of the two components forming the interface wherein the pretreatment provides a submicron-scale porosity with surface roughness greater than or equal to 50 Å rms.
2. The optical composite of claim 1 that contains a patterned structure at the interface between any two components.
3. The optical composite of claim 2 wherein the patterned structure depends on the crystallographic orientation of a single crystal.
4. The optical composite of claim 1 wherein the porous interface layer has antireflective properties.
5. The optical composite of claim 1 wherein the porous layer at the interface has an optical coating deposited.
6. The optical composite of claim 5 wherein the optical coating at the interface includes a transparent layer of carbon.
7. The optical composite of claim 5 wherein the optical coating at the interface includes one or more dielectric layers.
8. The optical composite of claim 1 with pre-etched channels in large-area interfaces to assist in venting trapped gas during optical contacting.
9. The optical composite of claim 1 wherein the bonding force of the composite has been reduced due to the reduced interfacial contact area.
10. An optical composite that comprises first and second components having complementary facing surfaces with an inert optical coating deposited on at least one of the facing surfaces prior to the first and second components being optically contacted, the optical coating impeding the formation of chemical bonds between the components, resulting in increasing the upper limit of heat treatment where the composite remains essentially stress-free.
11. The optical composite of claim 10 wherein the coating consists of transparent diamond-like carbon.
12. An optical composite comprising first and second components formed of dissimilar materials in optical contact at an interface wherein:
the first and second components were optically contacted using heat treatment over a temperature range;
an inert optical coating was applied to at least one of the first and second components prior to optical contacting; and
the temperature range of heat treatment is below the onset of chemical reactions at the interface; and
stresses developed between the dissimilar materials are relaxed by relative movement of the components parallel to the interface resulting in a stress-free or low-stress condition.
13. The optical composite of claim 12 wherein the inert optical coating comprises transparent carbon.
14. The optical composite of claim 12 wherein the optical composite consists of YAG and diamond.
15. An optical composite comprising:
a first component having a first surface; and
a second component having a second surface complementary to the first surface;
wherein,
the first and second components are in optical contact along an interface defined by the first and second surfaces; and
the first component has been pretreated to increase its porosity on the first surface wherein the pretreatment provides a submicron-scale porosity with surface roughness greater than or equal to 50 Å rms.
16. An optical composite comprising:
first and second components formed from dissimilar optical or electro-optical materials; and
a thin layer of diamond, selected from single crystal or polycrystalline diamond, applied to at least one of the first and second components prior to bonding the first and second components by optical contacting and heat treatment of the first and second components, wherein the inert property of the diamond provides improved bonding.
17. An optical composite consisting of a thin layer of initially free-standing diamond sheet sandwiched and bonded between two components formed from dissimilar and not directly compatible optical or electro-optical materials.
18. An optical composite consisting of at least two diamond components bonded to each other by optical contacting followed by heat treatment, selected from CVD polycrystalline, CVD single crystal, high-pressure grown single crystal and natural diamond.
19. The optical composite of claim 12 wherein the interface is a non-flat interface.
20. The optical composite of claim 19 , where the bonded materials have an interface of a shape selected from spherical, cylindrical, and aspheric.
21. The optical composite of claim 20 , where the bonded materials are processed into a disk consisting of a laser-active central section and a laser-inactive cladding section of circular cross section.
22. The optical composite of claim 1 wherein the pretreatment includes polishing to a surface roughness less than 50 Å rms followed by increasing the surface roughness to greater than or equal to 50 Å rms.
23. The optical composite of claim 15 wherein the pretreatment includes polishing to a surface roughness less than 50 Å rms followed by increasing the surface roughness to greater than or equal to 50 Å rms.
24. An optical composite comprising:
a first component having a first surface; and
a second component having a second surface complementary to the first surface;
wherein,
the first and second components are in optical contact along an interface defined by the first and second surfaces;
at least one component has been pretreated to form a pattern of channels on at least a portion of that component's respective surface to assist in venting trapped gas during a time when the first and second components are being brought into optical contact.
25. The optical composite of claim 24 , and further comprising an optical coating on at least a portion of at least one component's respective surface.
26. The optical composite of claim 24 wherein at least a portion of at least one component's respective surface has been pretreated to increase its surface roughness to provide a porous interface.
27. The optical composite of claim 24 wherein the first and second components are similar materials.
28. The optical composite of claim 24 wherein the first and second components are dissimilar materials.
29. An optical composite comprising:
a first component having a first surface; and
a second component having a second surface complementary to the first surface; and
an inert optical coating deposited on at least a portion of at least one component's respective surface;
wherein,
the optical coating becomes interposed between the first and second surfaces when the first and second components are brought into optical contact and subjected to heat treatment;
the optical coating impedes chemical reactions between the components during heat treatment so as to allow the relative movement of the components parallel to the interface during temperature changes and to increase the upper limit of heat treatment temperatures where the composite remains essentially stress-free.
30. The optical composite of claim 29 wherein the coating consists of transparent diamond-like carbon.
31. The optical composite of claim 12 wherein the optical composite consists of YAG and spinel.
32. The optical composite of claim 12 wherein the optical composite consists of YAG and silicon carbide.