Synthetic diamond optical mirrors

Patent metadata

Field	Value
Publication number	US-10191190-B2
Application number	US-201415102778-A
Country	US
Kind code	B2
Filing date	Dec 4, 2014
Priority date	Dec 9, 2013
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

A mirror for use in high power optical applications, the mirror comprising:
a support plate comprising a synthetic diamond material; and a reflective coating disposed over the support plate, wherein the reflective coating comprises a bonding layer of carbide forming material which bonds the reflective coating to the synthetic diamond material in the support plate, a reflective metal layer disposed over the bonding layer, and one or more layers of dielectric material disposed over the reflective metal layer, wherein the bonding layer and the reflective metal layer together have a total thickness in a range 50 nm to 10 μm with the reflective metal layer having a thickness of no more than 5 μm, and wherein the support plate and the reflective coating are configured such that the mirror has a reflectivity of at least 99% at an operational wavelength of the mirror.

First claim

The invention claimed is:

1. A mirror for use in high power optical applications, the mirror comprising:
a support plate comprising a synthetic diamond material; and
a reflective coating disposed over the support plate,
wherein the reflective coating comprises a bonding layer of carbide forming material selected from any of W, Cr, or Ti, which bonds the reflective coating to the synthetic diamond material in the support plate, a reflective metal layer disposed over the bonding layer, and one or more layers of dielectric material disposed over the reflective metal layer,
wherein the bonding layer and the reflective metal layer together have a total thickness in a range 50 nm to 10 μm with the reflective metal layer having a thickness of no more than 5 μm, and
wherein the support plate and the reflective coating are configured such that the mirror has a reflectivity of at least 99% at an operational wavelength of the mirror,
wherein the bonding layer and the reflective metal layer are formed of different materials, and
wherein the operational wavelength is one of 10.6 μm, 1.06 μm, 532 nm, 355 nm, or 266 nm.

2. A mirror according to claim 1 ,
wherein the thickness of the reflective metal layer is no more than 3 μm, 1 μm, 500 nm, or 300 nm.

3. A mirror according to claim 1 ,
wherein the thickness of the reflective metal layer is no less than 50 nm, 100 nm, 150 nm, or 200 nm.

4. A mirror according to claim 1 ,
wherein the reflective metal layer is formed of Au, Ag, Al, Mo, Cu, Ni, Rh, or W.

5. A mirror according to claim 1 ,
wherein the bonding layer has a thickness of no more than 500 nm, 250 nm, 150 nm, or 100 nm.

6. A mirror according to claim 5 ,
wherein the thickness of the bonding layer is no less than 10 nm, 20 nm, or 50 nm.

7. A mirror according to claim 1 ,
wherein the one or more layers of dielectric material have a total thickness of no more than 20 μm, 15 μm, 10 μm, or 5 μm.

8. A mirror according to claim 7 ,
wherein the total thickness of the one or more layers of dielectric material is no less than 0.5 μm, 1 μm, or 2 μm.

9. A mirror according to claim 1 ,
wherein the one or more layers of dielectric material comprise a stack of two or more dielectric layers disposed over the reflective metal layer, each dielectric layer having a thickness equal to one quarter of the operational wavelength of the mirror.

10. A mirror according to claim 1 ,
wherein the one or more layers of dielectric material are formed from one or more of ThF 4 , YbF 3 , BaF 2 , ZnSe, and/or ZnS.

11. A mirror according to claim 1 ,
wherein the reflective coating further comprises a barrier layer provided between the bonding layer and the reflective metal layer.

12. A mirror according to claim 11 ,
wherein the barrier layer has a thickness of no more than 500 nm, 250 nm, 150 nm, or 100 nm.

13. A mirror according to claim 12 ,
wherein the barrier layer is formed of platinum.

Assignees

• Element Six Tech Ltd

Inventors

• Dodson Joseph
• Anoikin Yevgeny Vasilievich
• Twitchen Daniel
• Mcclymont Mark Robin

Classifications

• G02B5/0858 Primary

  the reflecting layers comprising a single metallic layer with one or more dielectric layers · CPC title

• G02B1/02

  made of crystals, e.g. rock-salt, semi-conductors (G02B1/08 takes precedence) · CPC title

• G02B5/0891

  Ultraviolet [UV] mirrors (apparatus for microlithography exposure G03F7/70; X-ray multilayer structures G21K1/06) · CPC title

• G02B5/0808 Primary

  having a single reflecting layer (G02B5/0883, G02B5/0891 take precedence) · CPC title