System, method and apparatus for phase contrast enhanced multiplexing of images
A volume holographic imaging system, apparatus, and/or method enables the projection of a two-dimensional (2D) slice of a four-dimensional (4D) probing object. A 4D probing source object is illuminated to emit or scatter an optical field. A holographic element having one or more recorded holograms receives and diffracts the optical field into a diffracted plane beam having spectral information. A 4-f telecentric relay system includes a pupil filter on the relayed conjugate plane of the volume hologram and images the pupil of the volume hologram onto the front focal plane of the collector lens. A collector lens focuses the diffracted plane beam to a 2D slice of the 4D probing source object. The focused 2D slice is projected onto a 2D imaging plane. The holographic element may have multiple multiplexed holograms that are arranged to diffract light from the corresponding slice of the 4D probing source object.
1. An optical microscope comprising:
an objective lens for receiving and collimating optical spectrum electromagnetic radiation emitted or scattered from an object of interest;
a volume hologram with a plurality of multiplexed holographic gratings to receive and diffract the collimated optical spectrum electromagnetic radiation, each of the plurality of multiplexed holographic gratings being Bragg matched to diffract optical spectrum electromagnetic radiation corresponding to a different depth in the object of interest;
a relay system to receive and relay the diffracted collimated optical spectrum electromagnetic radiation from the volume hologram corresponding to the different depths in the object of interest;
a phase filter to receive and simultaneously filter the relayed collimated optical spectrum electromagnetic radiation from each of the different depths in the object of interest; and
a focusing lens to focus onto an imaging plane the collimated optical spectrum electromagnetic radiation that passes through the phase filter simultaneously forming a plurality of filtered two-dimensional images of the object of interest each corresponding to one of the different depths in the object of interest,
wherein the phase filter is located at the relayed conjugate plane of the volume hologram's pupil.
2. The microscope of claim 1 , wherein the volume hologram is transmissive.
3. The microscope of claim 1 , wherein the volume hologram is recorded in phenanthrenquinone doped poly methyl methacrylate.
4. The microscope of claim 1 , wherein the relay system is a 4-f telecentric relay system.
5. The microscope of claim 1 , further comprising a source of optical spectrum electromagnetic radiation.
6. The microscope of claim 1 , wherein the phase filter is a Zernike filter.
7. The microscope of claim 1 , wherein the phase filter is a knife edge filter.
8. A volume imaging system for imaging a source object comprising:
a transmissive holographic element having a plurality of multiplexed gratings recorded therein, the transmissive holographic element configured to receive and diffract an optical field emitted from the source object into a plurality of diffracted plane beams, each of the plurality of multiplexed gratings being Bragg matched to diffract a different two-dimensional slice of the optical field corresponding to a different depth in the source object;
collector optics including a 4-f telecentric relay system configured to:
focus each of the plurality of diffracted plane beams corresponding to the different two-dimensional slices of the optical field of the source object; and
for each of the plurality of diffracted plane beams, simultaneously project the corresponding focused two-dimensional slices of the optical field along an optical path onto an imaging plane; and
a phase filter disposed along the optical path at the relayed conjugate plane of a pupil of the transmissive holographic element to simultaneously eliminate the DC component in the spatial frequency domain of the focused two-dimensional slices of the optical field from the different depths of the source object.
9. The volume imaging system of claim 8 , wherein the collector optics include an imaging lens.
10. The volume imaging system of claim 9 , further comprising a source of optical spectrum electromagnetic radiation.
11. The volume imaging system of claim 10 , wherein the volume imaging system is configured to simultaneously diffract the different two-dimensional slices of the optical field corresponding to the different depths of the source object to non-overlapping regions of the imaging plane.
12. The volume imaging system of claim 11 , wherein the source object is defined in four dimensional space and real time.
13. The volume imaging system of claim 11 , wherein the phase filter is a Zernike filter.
14. The volume imaging system of claim 11 , wherein the phase filter is a knife edge filter.
15. A method for imaging an object in four-dimensions and real time comprising:
receiving an emitted or scattered optical field of an object in a transmissive holographic element, the transmissive holographic element having a plurality of multiplexed holographic gratings;
diffracting the received optical field in the holographic element to a plurality of diffracted plane beams, each of the multiplexed holographic gratings being Bragg matched to diffract the received optical field corresponding to a different depth in the source object;
forming, using relay lenses, Fourier transforms of the plurality of diffracted plane beams at an intermediate plane conjugate to a pupil of the transmissive holographic element;
filtering, simultaneously and at the intermediate plane, the Fourier transforms of the plurality of diffracted plane beams corresponding to different depths in the object; and
projecting the filtered Fourier transforms of each of the diffracted plane beams onto an imaging plane simultaneously, thereby forming a plurality of filtered two-dimensional images of the object, each corresponding to one of the different depths in the object.
16. The method of claim 15 , wherein the filtering step is performed using a knife edge filter.
17. The method of claim 15 , wherein the filtering step is performed using a Zernike filter.
18. The method of claim 15 , wherein the filtering step eliminates the DC component in the spatial frequency domain of each of the Fourier transforms of the plurality of diffracted plane beams corresponding to the different depths in the object.
19. The method of claim 15 , further comprising the step of processing the emitted optical field through objective optics.
20. The method of claim 19 , wherein the objective optics comprises a collimating lens configured to collimate the emitted optical field.
21. The method of claim 20 , wherein the objective optics is part of the holographic element.