Light returning target for a photometer
A light returning target for a photometer. The light returning target comprises a ball lens, and a cradle. The cradle has a hemispherical receptacle in which the lens is intimately received. Preferably, the lens is formed of fused silica, the receptacle is polished sufficiently to reflect, more than it scatters, light, and at least the surface of the receptacle is formed of a material that absorbs, more than it reflects, light.
1. A light returning target for a photometer, comprising:
a substantially spherical ball lens; and
a cradle having a matchingly hemispherical receptacle in which said lens is intimately received, said receptacle having a reflective surface for reflecting light passing through said lens.
2. The target of claim 1 , wherein said lens is formed of fused silica.
3. The target of claim 2 , wherein said surface is polished sufficiently to reflect, more than it scatters, light.
4. The target of claim 2 , wherein said receptacle absorbs, more than it reflects, light.
5. The target of claim 4 , wherein said surface is polished sufficiently to reflect, more than it scatters, light.
6. The target of claim 1 , wherein said receptacle absorbs, more than it reflects, light.
7. The target of claim 6 , wherein said surface is polished sufficiently to reflect, more than it scatters, light.
8. A photometer, comprising:
a light source which emits light along a line; and
a target, the target comprising a substantially spherical ball lens and a cradle having a matchingly hemispherical receptacle in which said lens is intimately received, said cradle being oriented so that said lens and said cradle together return at least a portion of the light along said line.
9. The photometer of claim 8 , further comprising a chamber, a light detector, and a light pipe set including a bifurcated optical fiber for conducting the light from said light source and emitting the light into said chamber along said line, and for conducting the light returned along said line from said chamber to said light detector, said target being disposed inside said chamber.
10. The photometer of claim 9 , wherein said chamber has an interior surface and further comprising a flow tube having one or more fluid inlets and one or more fluid outlets providing for fluid flow through said flow tube, said target being disposed within said flow tube, said flow tube having an interior surface that is smooth relative to said interior surface of said chamber, to help maintain laminar flow around said target.
11. The photometer of claim 9 , wherein said lens is formed of fused silica.
12. The photometer of claim 11 , wherein the surface of said receptacle is polished sufficiently to reflect, more than it scatters, the light.
13. The photometer of claim 12 , wherein said receptacle absorbs, more than it reflects, the light.
14. The photometer of claim 11 , wherein said receptacle absorbs, more than it reflects, the light.
15. The photometer of claim 8 , wherein said lens is formed of fused silica.
16. The photometer of claim 15 , wherein the surface of said receptacle is polished sufficiently to reflect, more than it scatters, the light.
17. The photometer of claim 15 , wherein said receptacle absorbs, more than it reflects, the light.
18. The photometer of claim 17 , wherein the surface of said receptacle is polished sufficiently to reflect, more than it scatters, the light.
19. The photometer of claim 8 , wherein said receptacle absorbs, more than it reflects, the light.
20. The photometer of claim 19 , wherein the surface of said receptacle is polished sufficiently to reflect, more than it scatters, the light.
21. A photometer, comprising:
a light source, wherein light emitted from said light source is made available as an output at a predetermined first point; and
a target, the target comprising a substantially spherical ball lens and a cradle having a matchingly hemispherical receptacle in which said lens is intimately received, said cradle being oriented so as to at least partially focus light received from said first point at a predetermined second point.
22. The photometer of claim 21 , further comprising a light detector and a light pipe set including a bifurcated optical fiber for coupling light emitted from said light source to said first point, and coupling light focused at said second point to said light detector.
23. The photometer of claim 22 , further comprising a chamber in which said target is disposed, wherein said chamber has an interior surface and further comprising a flow tube having one or more fluid inlets and one or more fluid outlets providing for fluid flow through said flow tube, said target being disposed within said flow tube, said flow tube having an interior surface that is smooth relative to said interior surface of said chamber, to help maintain laminar flow around said target.
24. The photometer of claim 22 , wherein said lens is formed of fused silica.
25. The photometer of claim 24 , wherein the surface of said receptacle is polished sufficiently to reflect, more than it scatters, light received thereby.
26. The photometer of claim 25 , wherein said receptacle absorbs, more than it reflects, light received thereby.
27. The photometer of claim 24 , wherein said receptacle absorbs, more than it reflects, light received thereby.
28. The photometer of claim 21 , wherein said lens is formed of fused silica.
29. The photometer of claim 28 , wherein the surface of said receptacle is polished sufficiently to reflect, more than it scatters, light received thereby.
30. The photometer of claim 28 , wherein said receptacle absorbs, more than it reflects, light received thereby.
31. The photometer of claim 30 , wherein the surface of said receptacle is polished sufficiently to reflect, more than it scatters, light received thereby.
32. The photometer of claim 21 , wherein said receptacle absorbs, more than it reflects, light received thereby.
33. The photometer of claim 32 , wherein the surface of said receptacle is polished sufficiently to reflect, more than it scatters, the light.