Field synthesis and optical subsectioning for standing wave microscopy

• US 5,801,881 A
• Filed: 02/23/1995
• Issued: 09/01/1998
• Est. Priority Date: 02/05/1993
• Status: Expired due to Term

• Current Assignee: Carnegie Mellon University
• Original Assignee: Carnegie Mellon University
• Inventors: Bailey, Brent, Taylor, D. Lansing, Lanni, Frederick
• Primary Examiner(s): NGUYEN, THONG Q
• Application Number:
  US08/392,496
• Time in Patent Office: 1,286 Days
• Field of Search: 359/368-390, 250/216, 250/234-236, 250/458.1, 250/459.1, 250/461.1
• US Class Current: 359/386
• CPC Class Codes: G02B 21/06 Means for illuminating specimens

Abstract

In an improved optical microscope for observing a luminescent specimen, the specimen is excited by a single, on axis or multiple superposed series of standing wave fields. Then an image of the specimen is recorded and displayed. This specimen can be incrementally moved and additional images can be recorded and processed. Images of the specimen recorded when there are nodes or antinodes at the focal plane of the microscope can be combined by image processing to produce an improved image or set of images of the specimen. Also disclosed are improved standing wave microscopes having a phase conjugator, a transmitted light source, feedback stabilization, an extended light source for field synthesis or a beam contractor. A multiple wavelength light source can be used to view a specimen marked with multiple luminescent dyes.

Claims

1. An apparatus comprising:

an extended incoherent light source;

a moveable beam splitter positioned such that light from said light source is imaged onto said beam splitter and split into an upper beam and a lower beam traveling in respective optical paths;

two objective lenses positionable to cause light beams passing through said lenses to form standing wave fields identically positioned relative to a plane of focus; and

,

a plurality of reflective surfaces positioned to orient and balance the respective optical paths of said upper and lower beams from the beam splitter to said plane to within the coherence length of said light beams with respect to each other and reflect said upper and lower beams through separate ones of said two objective lenses to generate a multiplicity of standing wave fields relative to said plane.

2. The apparatus of claim 1 further comprising at least one polarization mask between the light source and the beam splitter.

3. The apparatus of claim 1 further comprising at least one transmittance mask between the light source and the beam splitter.

4. The apparatus of claim 1, wherein said incoherent light source comprises a scrambled laser source.

5. The apparatus of claim 1, wherein said incoherent light source comprises a laser rapidly swept in a pattern across said beam splitter.

6. The apparatus of claim 1, wherein said beam splitter is moveable to shift the phase of one of said upper and lower beam path with respect to the other beam path.

7. The apparatus of claim 1 wherein said plurality of reflective surfaces further comprises an odd number of reflective surfaces for one of said upper and lower beams and an even number of reflective surfaces for the other of said beams.

8. The apparatus of claim 1 further comprising a wavelength filter positioned between said incoherent light source and said beam splitter to filter said light being imaged on said beam splitter.

9. The apparatus of claim 8 further comprising a polarizing filter positioned between said incoherent light source and said beam splitter to filter said light being imaged on said beam splitter.

10. The apparatus of claim 9 further comprising a camera positioned relative to one of said objective lenses to record an image at said plane of focus.

11. The apparatus of claim 10 further comprising an image processor connected to said camera to combine images recorded by said camera.

12. A method of producing standing waves relative to a plane of focus, said method comprising:

positioning two objective lenses to cause light beams passing through different said lenses to form standing wave fields identically positioned relative to a plane of focus

providing an extended incoherent light source to emit a light beam;

splitting the light beam emitted from the light source into upper and lower beams traveling in respective optical paths; and

,

reflecting the upper and lower light beams to orient and balance the respective optical paths of said upper and lower beams to the plane to within the coherence length of said light beams with respect to each other and to direct the upper and lower beam through separate ones of said objective lenses to generate a multiplicity of standing wave fields relative to the plane of focus.

13. The method of claim 12, further comprising polarizing the light beam to produce s-polarized standing waves in the specimen.

14. The method of claim 12, wherein said method includes recording an image at the plane of focus, said method further comprises:

labeling a specimen with a fluorescent or phosphorescent label that can be excited by the standing wave fields and emit light;

placing the specimen in the plane of focus; and

, recording a first image produced by the light emitted by the label.

15. The method of claim 14, further comprising:

shifting the phase of one of the upper and lower beams relative to the other beam;

recording a second image produced by the light emitted by the label; and

,

combining the first and second images to create a combined image.

16. The method of claim 15, further comprising polarizing the light beam to produce s-polarized standing waves in the specimen.

17. The method claim 16, wherein:

said splitting further comprises splitting the light beam to produce an intensity antinode at the plane; and

,

said shifting further comprises shifting the phase of one of the upper and lower beams relative to the other beam to produce an intensity node at the plane.

18. An apparatus comprising:

an extended incoherent light source;

a moveable beam splitter positioned such that light from said light source is imaged onto said beam splitter and split into an upper beam and a lower beam;

a polarizing filter positioned between said incoherent light source and said beam splitter to filter said light being imaged on said beam splitter;

a wavelength filter positioned between said incoherent light source and said beam splitter to filter said light being imaged on said beam splitter;

two objective lenses positionable to cause light beams passing through said lenses to form standing wave fields identically positioned relative to a plane of focus; and

,

a plurality of reflective surfaces positioned to orient and balance the optical paths of said upper and lower beams from the beam splitter to said plane to within the coherence length of said light beams with respect to each other and to reflect said upper and lower beams through separate ones of said two objective lens to generate a multiplicity of standing wave fields relative to said plane.

19. The apparatus of claim 18 further comprising a camera positioned relative to one of said objective lenses to record an image at said plane of focus.

20. The apparatus of claim 18 further comprising at least one transmittance mask positioned between said incoherent light source and said beam splitter to filter said light being imaged on said beam splitter.