Method for biomolecular detection and system thereof
A method of sensing at least one target on a receptor having a substrate and a translucent coating includes minimizing interference fringe patterns in an image of the target. The method also includes passing the image of the target through an imaging system intermediate the receptor and a detector.
1. A method of sensing at least one target on a receptor having a substrate and a translucent coating, the method comprising:
(a) passing a reflected beam through compensation optics intermediate the receptor and a detector; and
(b) minimizing interference patterns in an image of the target formed with the reflected beam.
2. The method of claim 1 , further comprising illuminating the target with coherent light.
3. The method of claim 1 , further comprising illuminating the target with a collimated beam.
4. The method of claim 1 , further comprising illuminating the target with a polarized beam of narrow-bandwidth light.
5. The method of claim 1 , further comprising employing a charge coupled device as the detector.
6. The method of claim 1 , further comprising locating an aperture optically intermediate a source of an illumination beam and a detector, the receptor being optically intermediate the source of the illumination beam and the detector.
7. The method of claim 1 , further comprising locating a spatial filter optically intermediate a source of an illumination beam and the receptor.
8. The method of claim 7 , further comprising including an objective lens and an optical pinhole in the spatial filter.
9. The method of claim 8 , further comprising including a plurality of lenses in the objective lens.
10. The method of claim 1 ,further comprising removing a p-wave component from an illumination beam impinging the target, and rotating polarization of the illumination beam optically upstream of the detector.
11. The method of claim 1 , wherein minimizing interference patterns comprises removing fringe patterns from the image of the target.
12. The method of claim 1 , further comprising expanding a diameter of an illumination beam impinging the target such that the expanded diameter is substantially equal to a length of the substrate.
13. The method of claim 12 , wherein the expanded beam has a uniform intensity.
14. The method of claim 1 , further comprising focusing a diverging illumination beam reflected by the receptor.
15. A method of sensing at least one target on a receptor having a substrate and a translucent coating, the method comprising:
(a) passing a reflected beam through compensation optics intermediate the receptor and a detector; and
(b) compensating for diffraction effects in an image of the target formed with the reflected beam.
16. The method of claim 15 , further comprising illuminating the target with coherent light.
17. The method of claim 15 , further comprising illuminating the target with a collimated beam.
18. The method of claim 15 , wherein the compensation optics comprises an Offner relay.
19. The method of claim 15 , further comprising employing a charge coupled device as the detector.
20. The method of claim 15 , further comprising locating an aperture optically intermediate a source of an illumination beam and a detector.
21. The method of claim 15 , further comprising locating a spatial filter optically intermediate of a source of an illumination beam and the receptor.
22. The method of claim 21 , further comprising including an objective lens and an optical pinhole in the spatial filter.
23. The method of claim 22 , further comprising including a plurality of lenses in the objective lens.
24. An apparatus for imaging a receptor on a substrate having a translucent coating, the apparatus comprising:
(a) a coherent light source generating a coherent beam along a beam path;
(b) a receptor disposed in the beam path to reflect the beam, the receptor forming a reflected beam along the beam path;
(c) a detector located in the beam path to image the reflected beam, the detector being mounted at an oblique angle relative to the reflected beam received by the detector; and
(d) compensation optics in the beam path optically intermediate the receptor and the detector.
25. The apparatus of claim 24 , wherein the compensation optics includes a plurality of optical surfaces.
26. The apparatus of claim 24 , further comprising an aperture optically intermediate the coherent light source and the receptor.
27. The apparatus of claim 24 , further comprising a spatial filter optically intermediate the coherent light source and the receptor.
28. The apparatus of claim 27 , wherein the spatial filter includes an objective and an optical pinhole.
29. The apparatus of claim 24 , wherein the compensation optics comprises a component of an Offner relay.
30. The apparatus of claim 24 , wherein the coherent beam is generated by the light source at an angle relative to the receptor.
31. The apparatus of claim 24 , wherein the oblique angle is substantially equal to a Brewster angle of the detector.