Off‐Axis Self‐Interference Holographic Imaging of an Incoherent 3‐D Scene Timothy Marshall 1 , Ziyi Zhu 2 , Darrick Hay 2 , Tim Holmstrom 1 , Myung Kim 2 , Zhimin Shi 2 , 1 Department of Physics, Longwood University, Farmville VA 23909 2 Department of Physics, University of South Florida, Tampa FL 33620 REU‐RET 2015 Poster Symposium, July 29, 2015 “This project is supported by the NSF REU grant # DMR-1263066: REU Site in Applied Physics at USF” Conclusions [1] J. Rosen and G. Brooker, Opt. Lett. 32, 912 (2007). [2] J. Hong & M. K. Kim, Opt. Lett. 38, 5196‐5199 (2013). Three‐dimensional (3D) imaging has diverse applications in biological imaging, surveillance, remote sensing, precision metrology, etc. In biological studies, for example, confocal microscopy is a widely used method for acquiring the 3D information of a biological sample. However, confocal microscopy requires a time‐consuming scanning process through the spatial points, and therefore cannot be used to capture some of the fast dynamics of the samples. In this work, we study an alternative approach to implement a 3‐D imaging modality using digital holography. To perform holographic imaging, one needs a signal field and a reference field to interfere and generate enough information in the intensity of the interferogram. For an incoherent scene, light from different points do not have any specific phase relations, meaning one needs to generate the signal and reference fields for each individual point sources. We here adopt a self‐interference digital holography concept introduced by Rosen et al. [1] and Hong et al. [2]. In addition, we wish to add two more features in our implementation to realizing robust imaging in real‐time. 1. A single‐shot measurement, enabling real‐time operation capability. 2. A common‐path configuration, meaning the setup is stable and vibration‐insensitive. Introduction Numerical Simulation Fig. 1 Schematic diagram of a polarization‐interferometry based self‐ interference holographic imaging system for a 3D incoherent scene. We here propose an off‐axis self‐interference holographic imaging modality. The off‐axis holography can retrieve the unambiguous phase information through filtering in the spatial frequency domain. The schematics of one implementation utilizing polarization interferometry is shown in Fig. 1. The key component to realize common path geometry is a chiral mirror that responds differently to two orthogonal polarization components, which serve as the necessary signal and reference beams that travels along the same path. It can be shown that through a filtering in the spatial frequency domain, one can obtain a complex‐value hologram given by the convolution of the transverse incoherent field distribution at a target plane and a Green’s function where is a parabolic phase determined by the distance from the source plane to the detection plane [2]. Theoretical Framework We have developed a Matlab code to numerically validate our scheme. The code is based on angular spectrum representation of arbitrary transverse field. Experimental Results We have demonstrated both numerically and experimentally a self‐referencing off‐axis holographic 3D imaging system based on polarization interferometry. Such capability is promising for monitoring a 3D scene, such as Fluorescence biological samples , in real time. References Recorded image Spatial Filtering Reconstructed scene of a single point source at 1.0 m Real Imaginary Reconstructed scene at different distances Z=0.75 m Z=1.0 m Z=1.25 m Z=1.5 m Z=0.75 m Z=1.0 m Z=1.25 m Z=1.5 m Z=0.7 m Z=0.85 m Z=1.0 m Z=1.15 m Reconstructed scene of two point sources at 0.7 m and 1.0 m, respectively
A scientific report on off axis holographic methods
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OffAxisSelfInterferenceHolographicImagingofanIncoherent3DSceneTimothyMarshall1,Ziyi
Zhu2,DarrickHay2,TimHolmstrom1,Myung
Kim2,ZhiminShi2,1DepartmentofPhysics,LongwoodUniversity,FarmvilleVA239092DepartmentofPhysics,UniversityofSouthFlorida,TampaFL33620REURET2015PosterSymposium,July29,2015This
project is supported by the NSF REU grant #DMR-1263066: REU Site in
Applied Physics at USFConclusions[1]
J.RosenandG.Brooker,Opt.Lett.32,912(2007).[2]J.Hong&M.K.Kim,Opt.Lett.
38,51965199(2013).Threedimensional (3D) imaging has diverse
applicationsin biological imaging, surveillance, remote sensing,
precisionmetrology,etc.In biologicalstudies,for
example,confocalmicroscopy is a widely used method for acquiring
the 3Dinformation of a biological sample. However,
confocalmicroscopy requires a timeconsuming scanning processthrough
the spatial points, and therefore cannot be used tocapture some of
the fast dynamics of the samples.In this work, we study an
alternative approach toimplement a 3D imaging modality using
digital holography. Toperform holographic imaging, one needs a
signal field and areference field to interfere and generate enough
information inthe intensity of the interferogram. For an incoherent
scene,light from different points do not have any specific
phaserelations,meaning one needs to generate the signalandreference
fields for each individual point sources. We hereadopt a
selfinterference digital holography concept introducedby Rosen et
al. [1] and Hong et al. [2].In addition, we wish to add two more
features in ourimplementation to realizing robust imaging in
realtime.1. A singleshot measurement, enabling realtime
operationcapability.2. A commonpath configuration, meaning the
setup is stableand
vibrationinsensitive.IntroductionNumericalSimulationFig.1Schematicdiagramofapolarizationinterferometrybasedselfinterferenceholographicimagingsystemfora3Dincoherentscene.We
here propose an offaxis selfinterference holographicimaging
modality. The offaxis holography can retrieve theunambiguous phase
information through filtering in the spatialfrequency domain.The
schematics of one implementationutilizing polarization
interferometry is shown in Fig. 1. The keycomponent to realize
common path geometry is a chiral mirrorthat responds differently to
two orthogonal polarizationcomponents, which serve as the necessary
signal and referencebeams that travels along the same path.It can
be shown that through a filtering in the spatialfrequency domain,
one can obtain a complexvalue hologramgiven by the convolution of
the transverse incoherent fielddistribution at a target plane and a
Greens functionwhere is a parabolic phase determined by the
distancefrom the source plane to the detection plane
[2].TheoreticalFrameworkWe have developed a Matlab code to
numerically validateour scheme. The code is based on angular
spectrumrepresentation of arbitrary transverse
field.ExperimentalResultsWe have demonstrated both numerically
andexperimentally a selfreferencing offaxis holographic 3Dimaging
system based on polarization interferometry. Suchcapability is
promising for monitoring a 3D scene, such asFluorescence biological
samples , in real time.ReferencesRecordedimage
SpatialFilteringReconstructedsceneofasinglepointsourceat1.0mReal
ImaginaryReconstructedsceneatdifferentdistancesZ=0.75m Z=1.0m
Z=1.25m Z=1.5mZ=0.75m Z=1.0m Z=1.25m Z=1.5mZ=0.7m Z=0.85m Z=1.0m
Z=1.15mReconstructedsceneof
twopointsourcesat0.7mand1.0m,respectively
