Annular optical device

• US 8,675,198 B2
• Filed: 08/01/2011
• Issued: 03/18/2014
• Est. Priority Date: 08/06/2010
• Status: Active Grant

• Current Assignee: Hach Company (Veralto Corp.)
• Original Assignee: Hach Company (Veralto Corp.)
• Inventors: Palumbo, Perry A.
• Primary Examiner(s): Toatley, Gregory J
• Assistant Examiner(s): Underwood, Jarreas C
• Application Number:
  US13/814,669
• Publication Number:
  US 20130135613A1
• Time in Patent Office: 960 Days
• Field of Search: 356335-344, 356432-444
• US Class Current: 356/338
• CPC Class Codes: G01N 15/06 Investigating concentration of particle suspensions by weighing G01N5/00; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10
• CPC Class Codes: G01N 15/075 by optical means
• CPC Class Codes: G01N 21/01 Arrangements or apparatus for facilitating the optical investigation
• CPC Class Codes: G01N 21/53 within a flowing fluid, e.g. smoke
• CPC Class Codes: G01N 2201/064 Stray light conditioning
• CPC Class Codes: G01N 33/18 Water
• CPC Class Codes: G02B 13/18 with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration G02B13/002 takes precedence
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0076 for use with a detector G02B19/009, G02B19/0095 take precedence
• CPC Class Codes: G02B 19/008 adapted to collect light from a complete hemisphere or a plane extending 360 degrees around the detector
• CPC Class Codes: G02B 2003/0093 characterised by the shape
• CPC Class Codes: G02B 26/0808 by means of one or more diffracting elements
• CPC Class Codes: G02B 3/04 with continuous faces that are rotationally symmetrical but deviate from a true sphere , e.g. so called "aspheric" lenses
• CPC Class Codes: G02B 5/001 Axicons, waxicons, reflaxicons
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

An annular optical device (100) includes an annular meso-optic (1) including an annulus (11) centered about an axis of revolution (A) and a secondary optical structure (2) substantially coaxial within the annulus (11). The secondary optical structure (2) and the annular meso-optic (1) are separated by a media (12) including a media refractive index that is lower than the refractive index of the secondary optical structure. The secondary optical structure (2) holds a specimen to be radiated by impinging electromagnetic radiation. Scattered radiation from the secondary optical structure (2) and within the annulus (11) of the annular meso-optic (1) is allowed into the annular meso-optic (1) if an angle of incidence of the scattered radiation exceeds a predetermined incidence threshold. The annular meso-optic (1) re-directs the scattered radiation to comprise re-directed radiation that is substantially parallel to the axis of revolution (A).

Claims

1. An annular optical device (100), comprising:

an annular meso-optic (1) including an annulus (11) centered about an axis of revolution (A); and

a secondary optical structure (2) substantially coaxial within the annulus (11) of the annular meso-optic (1), wherein the secondary optical structure (2) and the annular meso-optic (1) are separated by a media (12) including a media refractive index that is lower than a secondary optical structure refractive index, with the secondary optical structure (2) being configured to hold a specimen to be radiated by impinging electromagnetic radiation directed into the secondary optical structure (2) substantially along the axis of revolution (A), wherein scattered radiation from the secondary optical structure (2) and within the annulus (11) of the annular meso-optic (1) is allowed into the annular meso-optic (1) by the secondary optical structure (2) if an angle of incidence of the scattered radiation exceeds a predetermined incidence threshold and wherein the annular meso-optic (1) re-directs the scattered radiation to comprise re-directed radiation that is substantially parallel to the axis of revolution (A).

2. The annular optical device (100) of claim 1, wherein the scattered radiation received in the annular meso-optic (1) is substantially radially divergent from a line of focus (7) of the annular meso-optic (1), regardless of an angular separation of the impinging electromagnetic radiation from the axis of revolution (A).

3. The annular optical device (100) of claim 1, wherein the scattered radiation is received by the annular meso-optic (1) and re-directed substantially along the axis of revolution (A), wherein re-directed radiation exits from a planar annular optical surface (1d) of the annular meso-optic (1).

4. The annular optical device (100) of claim 1, wherein if the angle of incidence is less than the predetermined incidence threshold, then the scattered radiation is internally re-directed by the secondary optical structure (2) and cannot pass into the annular meso-optic (1).

5. The annular optical device (100) of claim 1, with the secondary optical structure (2) including a radiation-transmittable closed end (2c) that is configured to admit the impinging electromagnetic radiation.

6. The annular optical device (100) of claim 1, with the secondary optical structure (2) including at least one radiation-transmittable region about the line of focus (7) of the annular meso-optic (1).

7. The annular optical device (100) of claim 1, further comprising a radiation-blocking structure (4) positioned over or incorporated into at least a portion of the secondary optical structure (2), wherein the radiation-blocking structure (4) prevents radiation from leaving the secondary optical structure (2).

8. The annular optical device (100) of claim 1, further comprising a radiation-blocking structure (4) positioned over or incorporated into at least a portion of the secondary optical structure (2) and extending at least partially out from a planar annular optical surface (1d) of the annular meso-optic (1).

9. The annular optical device (100) of claim 1, further comprising a radiation-blocking structure (4) positioned over or incorporated into at least a portion of the secondary optical structure (2) and substantially centering the secondary optical structure (2) within the annulus (11) of the annular meso-optic (1).

10. A method of forming an annular optical device, the method comprising:

providing an annular meso-optic including an annulus centered about an axis of revolution; and

providing a secondary optical structure substantially coaxial within the annulus of the annular meso-optic, wherein the secondary optical structure and the annular meso-optic are separated by a media including a media refractive index that is lower than the refractive index of the secondary optical structure, with the secondary optical structure being configured to hold a specimen to be radiated by impinging electromagnetic radiation directed into the secondary optical structure substantially along the axis of revolution, wherein scattered radiation from the secondary optical structure and within the annulus of the annular meso-optic is allowed into the annular meso-optic by the secondary optical structure if an angle of incidence of the scattered radiation exceeds a predetermined incidence threshold and wherein the annular meso-optic re-directs the scattered radiation to comprise re-directed radiation that is substantially parallel to the axis of revolution.

11. The method of claim 10, wherein the scattered radiation received in the annular meso-optic is substantially radially divergent from a line of focus of the annular meso-optic, regardless of an angular separation of the impinging electromagnetic radiation from the axis of revolution.

12. The method of claim 10, wherein the scattered radiation is received by the annular meso-optic and re-directed substantially along the axis of revolution, wherein re-directed radiation exits from a planar annular optical surface of the annular meso-optic.

13. The method of claim 10, wherein if the angle of incidence is less than the predetermined incidence threshold, then the scattered radiation is internally re-directed by the secondary optical structure and cannot pass into the annular meso-optic.

14. The method of claim 10, with the secondary optical structure including a radiation-transmittable closed end that is configured to admit the impinging electromagnetic radiation.

15. The method of claim 10, with the secondary optical structure including at least one radiation-transmittable region about the line of focus of the annular meso-optic.

16. The method of claim 10, further comprising providing a radiation-absorbing structure positioned over or incorporated into at least a portion of the secondary optical structure, wherein the radiation-blocking structure prevents radiation from leaving the secondary optical structure.

17. The method of claim 10, further comprising providing a radiation-absorbing structure positioned over or incorporated into at least a portion of the secondary optical structure and extending at least partially out from a planar annular optical surface of the annular meso-optic.

18. The method of claim 10, further comprising providing a radiation-absorbing structure positioned over or incorporated into at least a portion of the secondary optical structure and substantially centering the secondary optical structure within the annulus of the annular meso-optic.