Device and method for calibration-free phase shifting procedure for self-interference holography
An apparatus and method are introduced to produce a hologram of an object from electromagnetic radiation, such as incoherent light, received from the object. The electromagnetic radiation is received by a receiving assembly and transformed into a plurality of co-linear co-propagating beams with different focal distances. The interference of the plurality of beams is enabled by projecting components of each beam along a common polarization direction. The interference patterns thus formed are recorded and then processed to form the hologram of the object.
1. An imaging device configured to produce super-resolved images of an object, said device comprising:
a means for receiving electromagnetic radiation from an object;
a means for imposing a linear polarization on at least one portion of the received electromagnetic radiation;
a birefringent lens assembly for producing a pair of two individual co-propagating linearly orthogonally polarized beams from each of the at least one linearly polarized portions of the received electromagnetic radiation, each individual co-propagating linearly orthogonally polarized beam bearing information about the shape and location of the object, and each individual co-propagating linearly orthogonally polarized beam having a distinct phase curvature from the other individual beam of the pair;
a wideband quarter waveplate for converting each pair of linearly orthogonally polarized beams into a pair of circularly orthogonally polarized beams without requiring wavelength calibration or otherwise changing their phase curvatures;
one of a linear polarizer or an array of differentially aligned micropolarizers for causing mutual interference between each individual of each pair of the circularly orthogonally polarized beams with the other individual of said pair, with controlled relative constant phase factors differing between the individuals;
means for recording at least one image of each the interference patterns by at least one imaging device; and
a computational means for producing holograms and reconstructed images of the object from the recorded images of the interference patterns.
2. The imaging device of claim 1 , wherein the received electromagnetic radiation is light in the range of ultraviolet to infrared.
3. The imaging device of claim 1 , wherein the means for imposing a linear polarization is a polarizing beam splitter that produces two differently linearly polarized portions of the electromagnetic radiation.
4. The imaging device of claim 3 , wherein:
each of the two polarized beams exiting the polarizing beam splitter is used as a said portion of the received electromagnetic radiation,
and wherein two pairs of orthogonally circularly polarized beams are produced, and wherein two imaging devices each produce at least one interference pattern from one or the other of the two portions.
5. The imaging device of claim 1 , wherein the means for imposing a linear polarization on the received electromagnetic radiation is the use of linearly polarized illumination.
6. The imaging device of claim 1 , wherein the one of a linear polarizer or an array of differentially aligned micropolarizers to cause mutual interference is at least one linear polarizer and wherein said imaging device records a single phase factor of each interference pattern in a single exposure.
7. The imaging device of claim 1 , wherein:
the one of a linear polarizer or an array of differentially aligned micropolarizers to cause mutual interference is at least one array of small polarizing elements, with each element possessing one of a set of n different polarization orientations,
wherein each element is registered to a specific location in the plane of the means to record the interference patterns, and
wherein said imaging device records n different constant phase factors of each interference pattern in a single exposure.
8. The imaging device of claim 1 , wherein:
the one of a linear polarizer or an array of differentially aligned micropolarizers to cause mutual interference is at least one array of small polarizing elements, with each element possessing one of a set of n different polarization orientations,
wherein each element is registered to a specific location in the plane of the means to record the interference patterns, and
wherein each location in the plane of the recording means simultaneously records multiple discrete colors, and
wherein said imaging device records n different constant phase factors of each interference pattern of each discrete color in a single exposure.
9. A method to produce super-resolved images of an object, including:
receiving electromagnetic radiation from an object;
imposing a linear polarization on at least one portion of the received electromagnetic radiation;
producing, using a birefringent lens assembly, a pair of two individual co-propagating linearly orthogonally polarized beams from each of the at least one linearly polarized portions of the received electromagnetic radiation, each individual co-propagating linearly orthogonally polarized beam bearing information about the shape and location of the object, and each individual co-propagating linearly orthogonally polarized beam having a distinct phase curvature from the other individual beam of the pair;
converting, using a wideband quarter waveplate, each pair of linearly orthogonally polarized beams into a pair of circularly orthogonally polarized beams using a wideband quarter waveplate without requiring wavelength calibration or otherwise changing their phase curvatures;
causing, using one of a linear polarizer or an art of differentially aligned micropolarizers, mutual interference between each individual of each pair of the circularly orthogonally polarized beams with the other individual of said pair, with controlled relative constant phase factors differing between the individuals;
recording at least one image of each the interference patterns by at least one imaging device; and
computationally operating on the recorded images of the interference patterns to produce holograms and reconstructed images of the object.
10. The method of claim 9 , wherein the imposition of a linear polarization is practiced by directing the received electromagnetic radiation through a polarizing beam splitter that produces two differently linearly polarized portions of the electromagnetic radiation.
11. The method of claim 10 , wherein:
each of the two polarized beams exiting the polarizing beam splitter is used as a said portion of the received electromagnetic radiation, and
wherein two pairs of orthogonally circularly polarized beams are produced, and wherein two imaging devices each produce at least one interference pattern from one or the other of the two portions.
12. The method of claim 11 , wherein the images recorded by the two imaging devices are processed together by coincidence imaging to increase signal to noise ratio in the recording process.
13. The method of claim 11 , wherein the images recorded by the two imaging devices are processed with compressive sensing methods to produce holograms and reconstructed images of the object.
14. The method of claim 9 , wherein the imposition of a linear polarization is practiced by illuminating the sample with linearly polarized electromagnetic radiation.
15. The method of claim 9 , wherein:
the causing mutual interference is practiced by directing each pair circularly orthogonally polarized beams through a linear polarizer and
wherein the recording of at least one image of the interference patterns is practiced by recording a single phase factor of each interference pattern in a single exposure.
16. The method of claim 9 , wherein:
the causing mutual interference is practiced by directing each pair circularly orthogonally polarized beams through an array of small polarizing elements, with each element possessing one of a set of n different polarization orientations,
wherein each element is registered to a specific location in the plane of a means for recording of at least one image of the interference patterns, and
wherein the recording of at least one image of the interference patterns is practiced by recording n different phase factors of each interference pattern in a single exposure.
17. The method of claim 9 , wherein:
the causing mutual interference is practiced by directing each pair circularly orthogonally polarized beams through an array of small polarizing elements, with each element possessing one of a set of n different polarization orientations,
wherein each element is registered to a specific location in the plane of a means for recording of at least one image of the interference patterns, and
wherein each location in the plane of said recording means simultaneously records multiple discrete colors, and
wherein the recording of at least one image of the interference patterns is practiced by recording n different phase factors of each interference pattern of each discrete color in a single exposure.