Method of manufacturing monolithic optical systems
Disclosed are monolithic optical systems using an aerogel molded around a mandrel. A method of manufacturing an optical system includes applying a reflective coating to at least a portion of a surface of a mandrel, placing the mandrel in a tank and subsequently filling the tank with aerogel to a predetermined depth below a top of the mandrel. The method includes adding a separation layer to the tank on top of the aerogel at the predetermined depth, catalyzing the separation layer into a solid, and adding aerogel on top of the separation layer filling the tank with aerogel above a height of the mandrel, and removing the aerogel and mandrel from the tank, drying the aerogel into a solid aerogel structure, catalyzing the reflective coating to bond the reflective coating with the aerogel, and removing the mandrel from the aerogel structure to produce the aerogel structure having a hollowed-out interior.
1. A method of manufacturing an optical system, the method comprising:
applying a reflective coating to at least a portion of a surface of a mandrel;
placing the mandrel in a tank and subsequently filling the tank with aerogel to a predetermined depth below a top of the mandrel;
adding a separation layer to the tank on top of the aerogel at the predetermined depth, and catalyzing the separation layer into a solid;
adding aerogel on top of the separation layer filling the tank with aerogel above a height of the mandrel;
removing the aerogel and mandrel from the tank;
drying the aerogel into a solid aerogel structure;
catalyzing the reflective coating to bond the reflective coating with the aerogel; and
removing the mandrel from the solid aerogel structure to produce a hollowed-out aerogel structure.
2. The method of claim 1 , wherein the removing the mandrel comprises:
separating a top portion of the solid aerogel structure from a bottom portion of the solid aerogel structure; and
bonding together the top portion of the solid aerogel structure to the bottom portion of the solid aerogel structure after the mandrel has been removed.
3. The method of claim 1 , further comprising:
applying a lifting layer before applying the reflective coating.
4. The method of claim 1 , further comprising:
applying an aerogel bonding layer to the reflective coating after applying the reflective coating and before submerging the mandrel.
5. The method of claim 4 , wherein the aerogel bonding layer is cured by heating the aerogel and the reflective coating.
6. The method of claim 1 , further comprising:
cutting holes in one or both of a top portion or a bottom portion of the solid aerogel structure to provide an unobstructed path for light to reach into or exit the optical system.
7. The method of claim 2 , further comprising:
providing a protective structure abound one or both of the bonded top or bottom portions.
8. The method of claim 1 , further comprising:
etching the separation layer using an etchant.
9. The method of claim 8 , wherein the etchant is aqua regia.
10. The method of claim 8 , wherein the reflective coating is applied to two or more surfaces of the mandrel.
11. The method of claim 1 , wherein the separation layer floats on top of the aerogel.
12. The method of claim 1 , wherein the drying the aerogel is supercritically drying the aerogel.
13. The method of claim 1 , wherein the tank includes a support structure to mechanically support the mandrel in the tank.
14. The method of claim 1 , wherein the aerogel is tetraethyl orthosilicate.
15. The method of claim 1 , wherein the aerogel is a silica aerogel.
16. The method of claim 1 , wherein the reflective coating is applied to two surfaces of the mandrel to produce two mirrors in the solid aerogel structure.
17. The method of claim 1 , wherein the reflective coating is applied to one surface of the mandrel to produce one mirror in the solid aerogel structure.