Aperture scanning fourier ptychographic imaging
Certain aspects pertain to aperture-scanning Fourier ptychographic imaging devices comprising an aperture scanner that can generate an aperture at different locations at an intermediate plane of an optical arrangement, and a detector that can acquire lower resolution intensity images for different aperture locations, and wherein a higher resolution complex image may be constructed by iteratively updating regions in Fourier space with the acquired lower resolution images.
1. A Fourier ptychographic imaging device, comprising:
a first lens configured to receive light issuing from a sample being imaged while the sample is illuminated by an illumination source during operation;
a spatial light modulator configured to generate, during operation, an aperture in an intermediate plane at a plurality of aperture locations at different acquisition times, the aperture configured to transmit light transmitted by the first lens during operation, wherein the plurality of aperture locations correspond to overlapping regions in the Fourier domain;
a second lens configured to receive, during operation, light transmitted by the aperture; and
a radiation detector configured to receive light transmitted by the second lens and to acquire a plurality of intensity measurements during operation.
2. The Fourier ptychographic imaging device of claim 1 , further comprising a processor configured to execute, during operation, instructions for constructing a complex image of the sample being imaged using the acquired intensity measurements.
3. The Fourier ptychographic imaging device of claim 2 , wherein the complex image is constructed by iteratively updating the overlapping regions in Fourier domain with data from the acquired intensity measurements during operation.
4. The Fourier ptychographic imaging device of claim 1 , wherein the spatial light modulator comprises a reflective liquid-crystal on silicon display or a digital micromirror device for providing the aperture.
5. The Fourier ptychographic imaging device of claim 1 , wherein the intermediate plane is a Fourier plane to a sample plane of the sample being imaged.
6. The Fourier ptychographic imaging device of claim 1 , wherein each of the plurality of intensity measurements acquired by the radiation detector uniquely corresponds to a different aperture location of the plurality of aperture locations.
7. The Fourier ptychographic imaging device of claim 1 , wherein:
the first lens is a convex lens having a first focal length and is located with an optical the first focal length from the sample plane,
the second lens is a convex lens having a second focal length and is located the second focal length from the intermediate plane,
the intermediate plane is located the first focal length away from the first lens, and
the intermediate plane is located the second focal length away from the second lens.
8. The Fourier ptychographic imaging device of claim 7 , wherein the first focal length is approximately the same as the second focal length to form a 4f configuration.
9. The Fourier ptychographic imaging device of claim 7 , wherein the radiation detector is located the first focal length from the second lens.
10. The Fourier ptychographic imaging device of claim 1 ,
wherein the spatial light modulator is further configured to provide additional apertures, during operation, to form a plurality of apertures at at least one acquisition time,
wherein the second lens receives light, during operation, transmitted through the plurality of apertures at the at least one of the acquisition times, wherein the acquired intensity measurement at the at least one acquisition time is associated with light transmitted through the corresponding plurality of apertures.
11. The Fourier ptychographic imaging device of claim 1 , wherein the overlapping areas in the Fourier domain overlap by at least about 70% of the aperture area.
12. The Fourier ptychographic imaging device of claim 1 , wherein overlapping areas in the Fourier domain overlap by between 20% and 90% of the aperture area.
13. The Fourier ptychographic imaging device of claim 1 , wherein the illumination source and the first lens are on one side of the sample being imaged.
14. The Fourier ptychographic imaging device of claim 1 , wherein the spatial light modulator comprises a display located at the intermediate plane, the display configured to display the aperture during operation.
15. The Fourier ptychographic imaging device of claim 1 , wherein the spatial light modulator is a digital micromirror device having one or more mirrors, wherein the digital micromirror device is configured to rotate one or more of the mirrors during operation to position the mirrors such that light is transmitted through the aperture in the intermediate plane and reflected from one or more of the mirrors at other locations in the intermediate plane.
16. A Fourier ptychographic imaging method, comprising:
causing an aperture to be located at a plurality of locations at a plurality of acquisition times, wherein the aperture is located at about a Fourier plane to a sample plane of a sample being imaged, wherein the aperture receives light issuing from the illuminated sample through a first lens during operation, wherein the plurality of locations correspond to overlapping regions in the Fourier domain; and
constructing an image of the sample by iteratively updating the overlapping regions in the Fourier domain with a plurality of intensity measurements taken by a radiation detector at the plurality of acquisition times, the plurality of intensity measurements based on light focused by a lens that is transmitted through the aperture at the plurality of acquisition times.
17. The Fourier ptychographic imaging method of claim 16 , further comprising generating additional apertures at the Fourier plane to form a plurality of apertures at each acquisition time.
18. The Fourier ptychographic imaging method of claim 16 , wherein the plurality of intensity measurements captured by the radiation detector uniquely correspond to different aperture locations of the plurality of aperture locations.
19. The Fourier ptychographic imaging method of claim 16 , wherein the overlapping areas in the Fourier domain overlap by at least about 70% of an area of the aperture.
20. The Fourier ptychographic imaging methon of claim 16 , wherein constructing the image of the sample comprises:
(a) initializing a current image in the Fourier domain;
(b) filtering an overlapping region of the current image in the Fourier domain to generate an intensity image for a corresponding aperture location of the plurality of aperture locations;
(c) replacing the data of the intensity image with an intensity measurement; and
(d) updating the overlapping region in the Fourier domain with the intensity image based on the intensity measurement.
21. The Fourier ptychographic imaging method of claim 16 , wherein causing the aperture to be located at a plurality of locations at the plurality of acquisition times comprises activating display elements of a reflective liquid-crystal on silicon display corresponding to the respective location.
22. The Fourier ptychographic imaging method of claim 16 , wherein causing the aperture to be located at a plurality of locations at the plurality of acquisition times comprises rotating one or more micromirrors of a digital micromirror device to an angular position corresponding to the respective location.