Surface preparation method for eliminating optical interference from absorption cavity mirrors

• US 8,317,342 B2
• Filed: 10/01/2009
• Issued: 11/27/2012
• Est. Priority Date: 07/11/2008
• Status: Active Grant

• Current Assignee: Li & S Company Limited (Yesco Holdings Co., Ltd.)
• Original Assignee: Li & S Company Limited (Yesco Holdings Co., Ltd.)
• Inventors: Anderson, Tyler
• Primary Examiner(s): Doak, Jennifer L.
• Application Number:
  US12/572,159
• Publication Number:
  US 20100091290A1
• Time in Patent Office: 1,153 Days
• Field of Search: 359838-884, 359/900
• US Class Current: 359/839
• CPC Class Codes: G01N 2021/0389 Windows
• CPC Class Codes: G01N 2021/152 Scraping; Brushing; Moving band
• CPC Class Codes: G01N 21/031 Multipass arrangements
• CPC Class Codes: G02B 5/0221 the surface having an irregular structure G02B5/0226 takes precedence
• CPC Class Codes: G02B 5/0284 used in reflection
• CPC Class Codes: G02B 5/08 Mirrors vehicle mirrors involving special optical features B60R1/08
• CPC Class Codes: G02B 5/0816 Multilayer mirrors, i.e. having two or more reflecting layers G02B5/0883, G02B5/0891 take precedence
• CPC Class Codes: G02B 5/0833 comprising inorganic materials only

Abstract

Optical mirror elements having a diffusive backing, methods for making such optical mirror elements, and devices incorporating such optical mirror elements. The optical mirror element typically includes a first, reflective surface, and a second surface having uneven or granular features, wherein light passing through the first surface is diffusely reflected by the uneven or granular features of the second surface. The optical mirror elements are particularly well suited for use in Herriott Cell arrangements in gas analyzers.

Claims

1. An optical mirror element integrated in a gas analyzer, the optical mirror element comprising:

a first, reflective surface that reflects a substantial portion of light in a specific wavelength range impinging thereon; and

a second surface, opposite the first surface, having a first portion with uneven or granular features, wherein any light in said specific wavelength range passing through the first surface and impinging on the first portion of the second surface is diffusely reflected by the uneven or granular features of the first portion of the second surface, wherein the optical mirror element is integrated in a gas analyzer.

2. The optical mirror element of claim 1, wherein the first, reflective surface includes one or more layers of dielectric material.

3. The optical element of claim 1, wherein the uneven or granular features are formed by sandblasting the second surface.

4. The optical element of claim 1, wherein the uneven or granular features are formed by removing material from the second surface.

5. The optical element of claim 1, wherein the uneven or granular features are formed by adding material to the second surface.

6. The optical mirror element of claim 1, wherein the second surface includes a second portion that defines an optically transmissive window portion, wherein any light in said specific wavelength range passing through the first surface and impinging on the window portion of the second surface passes through said window portion.