# Holographic microscopy ## expand\_more We use a fast imaging method called *holographic microscopy* to watch self-assembling systems. In a holographic microscope, the sample is illuminated by laser light, and the resulting image (or hologram) can be used to determine the 3D structure, position, and orientation of a microscopic sample. We build new holographic microscopes and develop software to analyze the holograms. ## An introduction to holography Dennis Gabor developed holography in the 1940s as a way to improve the resolving power of electron microscopes. However, his ideas apply to imaging with any coherent source. With the development of lasers in the 1960s, it became possible to do holographic recording and reconstruction with visible light and photographic film. Later, when CCD and CMOS cameras arrived on the scene, holograms could be recorded digitally. Today, with high-speed computers, we can not only record holograms digitally, but also reconstruct them digitally as well. To understand holography, we need to consider the wave nature of light. At any point in space, a light wave can be described by an amplitude and phase. Whereas a conventional photograph captures the intensity of light reflected or scattered from an object, a hologram can capture both amplitude and phase. This is because the hologram is recorded by using two light beams, one of which (called the object beam) is scattered from the object, and other (called the reference beam) is aimed at the camera. If the two waves are *coherent* (meaning the phase is well-defined at each point in space), they can interfere, or beat, with each other to produce interference fringes, like this: ![Light scatters off a particle, and an interference pattern i.e. hologram is created.](/sites/g/files/omnuum4256/files/styles/hwp_1_1__360x360_scale/public/manoharan/files/ryan_dhm1.jpeg?itok=WspE2vvQ) In the picture above, the small blue particle is illuminated by the red beam. It scatters light into an object beam, shown as a cone radiating from the sphere. That object beam interferes with the red beam to produce a fring pattern, shown on the right side of the image. The fringes encode information about the phase of light and, implicitly, about the position and structure of the object. That information can be recovered through *reconstruction.* The simplest way to recover the 3D information is to record the hologram as an intensity pattern on a camera. If, say, we take the image and print it on photographic film, we can then shine light back through it. The hologram will diffract the light so that an image of the object will become visible: ![A reference beam propagating back through a hologram will be focussed to a point close to where the original object was](/sites/g/files/omnuum4256/files/styles/hwp_1_1__360x360_scale/public/manoharan/files/ryan_dhm2.jpeg?itok=Nw-wabb3) This can most easily be understood if one imagines recording the hologram of a spherically scattered wave (like the light scattered from a microscopic particle). If one interferes that spherical wave coming from the object with a plane wave, a pattern of concentric rings will be observed. These fringes will resemble a Fresnel zone plate. And, just like a Fresnel zone plate, the fringes will focus a plane wave illuminating it to a point. In our lab, we build holographic microscopes, and we develop techniques for doing 3D reconstruction on a computer. Below are some of the techniques we use. ## In-line holographic microscopy The in-line holographic microscope operates as described above. A laser illuminates the sample, which is typically a colloidal or biological sample suspended in a liquid. Some of that light passes through the sample and acts as the reference beam, and some light is scattered by the object. We record the hologram on a CMOS camera, and we reconstruct it on a computer to recover 3D information about the sample. We can do the numerical equivalent of shining the reference beam back on the hologram and looking at the diffracted image, or, if we know what our object is beforehand, we can numerically fit a scattering model to the observed hologram using our software package, [HoloPy](https://github.com/manoharan-lab/holopy). We are currently able to track micron-scale spheres to a precision of less than 1 nm precision in all three dimensions, at high frame rates (over 5000 frames/second). We are also able to track clusters of spheres, and non-spherical particles and their rotations in 3-dimensions to a spatial precision of about 10 nm . Below is a video showing (on the left) a series of holograms taken of a 0.37 x 1.05 um polystyrene ellipsoid diffusing in water and (on the right) a rendering of the particle, showing the 3D position and orientation we infer from fitting a model to the recorded holograms. The movie is sped up by a factor of 5 from real time. ## Publications Download 25 citations download- [BibTeX](/bibcite/export?pager_style=no_pager&number_of_items=30&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchareas%5D%5B0%5D%5Btarget_id%5D=14681&&&format=bibtex) - [EndNote X3 XML](/bibcite/export?pager_style=no_pager&number_of_items=30&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchareas%5D%5B0%5D%5Btarget_id%5D=14681&&&format=endnote8) - [EndNote 7 XML](/bibcite/export?pager_style=no_pager&number_of_items=30&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchareas%5D%5B0%5D%5Btarget_id%5D=14681&&&format=endnote7) - [Endnote tagged](/bibcite/export?pager_style=no_pager&number_of_items=30&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchareas%5D%5B0%5D%5Btarget_id%5D=14681&&&format=tagged) - [Marc](/bibcite/export?pager_style=no_pager&number_of_items=30&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchareas%5D%5B0%5D%5Btarget_id%5D=14681&&&format=marc) - [PubMedId](/bibcite/export?pager_style=no_pager&number_of_items=30&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchareas%5D%5B0%5D%5Btarget_id%5D=14681&&&format=pubmed_id) - [RIS](/bibcite/export?pager_style=no_pager&number_of_items=30&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchareas%5D%5B0%5D%5Btarget_id%5D=14681&&&format=ris) ### 2023 Wit, X. M.; Paine, A. W.; Martin, C.; Goldfain, A. M.; Garmann, R. F.; Manoharan, V. N. [Precise Characterization of Nanometer-Scale Systems Using Interferometric Scattering Microscopy and Bayesian Analysis](/publications/precise-characterization-nanometer-scale-systems-using-interferometric). *Applied Optics* **2023**, *62* (27), 7205-7215. Wit, X. M.; Paine, A. W.; Martin, C.; Goldfain, A. M.; Garmann, R. F.; Manoharan, V. N. [Precise Characterization of Nanometer-Scale Systems Using Interferometric Scattering Microscopy and Bayesian Analysis](/publications/precise-characterization-nanometer-scale-systems-using-interferometric). *Applied Optics* **2023**, *62* (27), 7205-7215. - [ descriptionPublisher's Version](https://opg.optica.org/ao/abstract.cfm?uri=ao-62-27-7205) - [ descriptionPublisher's Version](https://opg.optica.org/ao/abstract.cfm?uri=ao-62-27-7205) ### 2022 Martin, C.; Altman, L. E.; Rawat, S.; Wang, A.; Grier, D. G.; Manoharan, V. N. [In-Line Holographic Microscopy With Model-Based Analysis](/publications/line-holographic-microscopy-model-based-analysis). *Nature Reviews Methods Primers* **2022**, *2* (1), 83. Martin, C.; Altman, L. E.; Rawat, S.; Wang, A.; Grier, D. G.; Manoharan, V. N. [In-Line Holographic Microscopy With Model-Based Analysis](/publications/line-holographic-microscopy-model-based-analysis). *Nature Reviews Methods Primers* **2022**, *2* (1), 83. - [ descriptionPublisher's Version](https://www.nature.com/articles/s43586-022-00165-z) - [ descriptionPublisher's Version](https://www.nature.com/articles/s43586-022-00165-z) ### 2021 Martin, C.; Leahy, B.; Manoharan, V. N. [Improving Holographic Particle Characterization by Modeling Spherical Aberration](/publications/improving-holographic-particle-characterization-modeling-spherical-aberration). *Optics Express* **2021**, *29* (12), 18212-18223. Martin, C.; Leahy, B.; Manoharan, V. N. [Improving Holographic Particle Characterization by Modeling Spherical Aberration](/publications/improving-holographic-particle-characterization-modeling-spherical-aberration). *Optics Express* **2021**, *29* (12), 18212-18223. - [ descriptionPublisher's Version](https://opg.optica.org/oe/fulltext.cfm?uri=oe-29-12-18212&id=451440) - [ descriptionPublisher's Version](https://opg.optica.org/oe/fulltext.cfm?uri=oe-29-12-18212&id=451440) ### 2020 Leahy, B.; Alexander, R.; Martin, C.; Barkley, S.; Manoharan, V. N. [Large Depth-of-Field Tracking of Colloidal Spheres in Holographic Microscopy by Modeling the Objective Lens](/publications/large-depth-field-tracking-colloidal-spheres-holographic-microscopy-modeling). *Optics Express* **2020**, *28* (2), 1061-1075. Leahy, B.; Alexander, R.; Martin, C.; Barkley, S.; Manoharan, V. N. [Large Depth-of-Field Tracking of Colloidal Spheres in Holographic Microscopy by Modeling the Objective Lens](/publications/large-depth-field-tracking-colloidal-spheres-holographic-microscopy-modeling). *Optics Express* **2020**, *28* (2), 1061-1075. - [ descriptionPublisher's Version](https://opg.optica.org/oe/fulltext.cfm?uri=oe-28-2-1061&id=425675) - [ descriptionPublisher's Version](https://opg.optica.org/oe/fulltext.cfm?uri=oe-28-2-1061&id=425675) Alexander, R.; Leahy, B.; Manoharan, V. N. [Precise Measurements in Digital Holographic Microscopy by Modeling the Optical Train](/publications/precise-measurements-digital-holographic-microscopy-modeling-optical-train). *Journal of Applied Physics* **2020**, *128* (6). Alexander, R.; Leahy, B.; Manoharan, V. N. [Precise Measurements in Digital Holographic Microscopy by Modeling the Optical Train](/publications/precise-measurements-digital-holographic-microscopy-modeling-optical-train). *Journal of Applied Physics* **2020**, *128* (6). - [ descriptionPublisher's Version](https://pubs.aip.org/aip/jap/article/128/6/060902/1063708) - [ descriptionPublisher's Version](https://pubs.aip.org/aip/jap/article/128/6/060902/1063708) ### 2019 Barkley, S.; Dimiduk, T. G.; Fung, J.; Kaz, D. M.; Manoharan, V. N.; McGorty, R.; Perry, R. W.; Wang, A. [Holographic Microscopy With Python and HoloPy](/publications/holographic-microscopy-python-and-holopy). *Computing in Science & Engineering* **2019**, *22* (5), 72-82. Barkley, S.; Dimiduk, T. G.; Fung, J.; Kaz, D. M.; Manoharan, V. N.; McGorty, R.; Perry, R. W.; Wang, A. [Holographic Microscopy With Python and HoloPy](/publications/holographic-microscopy-python-and-holopy). *Computing in Science & Engineering* **2019**, *22* (5), 72-82. - [ descriptionPublisher's Version](https://ieeexplore.ieee.org/abstract/document/8742661) - [ descriptionPublisher's Version](https://ieeexplore.ieee.org/abstract/document/8742661) ### 2016 Wang, A.; Garmann, R. F.; Manoharan, V. N. [Tracking E. Coli Runs and Tumbles With Scattering Solutions and Digital Holographic Microscopy](/publications/tracking-e-coli-runs-and-tumbles-scattering-solutions-and-digital-holographic). *Optics Express* **2016**, *24* (21), 23719–23725. https://doi.org/10.1364/OE.24.023719. Wang, A.; Garmann, R. F.; Manoharan, V. N. [Tracking E. Coli Runs and Tumbles With Scattering Solutions and Digital Holographic Microscopy](/publications/tracking-e-coli-runs-and-tumbles-scattering-solutions-and-digital-holographic). *Optics Express* **2016**, *24* (21), 23719–23725. https://doi.org/10.1364/OE.24.023719. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://www.opticsexpress.org/abstract.cfm?URI=oe-24-21-23719) - [ picture\_as\_pdfWang et al. - 2016 - Trac...](/sites/g/files/omnuum4256/files/manoharan/files/Wang_Tracking_E-coli_2016.pdf) We use in-line digital holographic microscopy to image freely swimming E. coli. We show that fitting a light scattering model to E. coli holograms can yield quantitative information about the bacterium&\\#x02019;s body rotation and tumbles, offering a... - [ descriptionPublisher's Version](http://www.opticsexpress.org/abstract.cfm?URI=oe-24-21-23719) - [ picture\_as\_pdfWang et al. - 2016 - Trac...](/sites/g/files/omnuum4256/files/manoharan/files/Wang_Tracking_E-coli_2016.pdf) Dimiduk, T. G.; Manoharan, V. N. [Bayesian Approach to Analyzing Holograms of Colloidal Particles](/publications/bayesian-approach-analyzing-holograms-colloidal-particles). *Optics Express* **2016**, *24* (21), 24045–24060. https://doi.org/10.1364/OE.24.024045. Dimiduk, T. G.; Manoharan, V. N. [Bayesian Approach to Analyzing Holograms of Colloidal Particles](/publications/bayesian-approach-analyzing-holograms-colloidal-particles). *Optics Express* **2016**, *24* (21), 24045–24060. https://doi.org/10.1364/OE.24.024045. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://www.opticsexpress.org/abstract.cfm?URI=oe-24-21-24045) - [ picture\_as\_pdfDimiduk and Manoharan - 2...](/sites/g/files/omnuum4256/files/manoharan/files/bayesian-holography.pdf) We demonstrate a Bayesian approach to tracking and characterizing colloidal particles from in-line digital holograms. We model the formation of the hologram using Lorenz-Mie theory. We then use a tempered Markov-chain Monte Carlo method to sample the... - [ descriptionPublisher's Version](http://www.opticsexpress.org/abstract.cfm?URI=oe-24-21-24045) - [ picture\_as\_pdfDimiduk and Manoharan - 2...](/sites/g/files/omnuum4256/files/manoharan/files/bayesian-holography.pdf) Goldfain, A.; Garmann, R.; Jin, Y.; Lahini, Y.; Manoharan, V. N. [Dynamic Measurements of the Position, Orientation, and DNA Content of Individual Unlabeled Bacteriophages](/publications/dynamic-measurements-position-orientation-and-dna-content-individual). *The Journal of Physical Chemistry B* **2016**, *120* (26), 6130–6138. Goldfain, A.; Garmann, R.; Jin, Y.; Lahini, Y.; Manoharan, V. N. [Dynamic Measurements of the Position, Orientation, and DNA Content of Individual Unlabeled Bacteriophages](/publications/dynamic-measurements-position-orientation-and-dna-content-individual). *The Journal of Physical Chemistry B* **2016**, *120* (26), 6130–6138. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dx.doi.org/10.1021/acs.jpcb.6b02153) - [ picture\_as\_pdfGoldfain et al. - 2016 - ...](/sites/g/files/omnuum4256/files/manoharan/files/goldfain_et_al._-_2016_-_dynamic_measurements_of_the_position_orientation_and_dna_content_of_individual_unlabeled_bacteriophages.pdf) A complete understanding of the cellular pathways involved in viral infections will ultimately require a diverse arsenal of experimental techniques, including methods for tracking individual viruses and their interactions with the host. Here we... - [ descriptionPublisher's Version](http://dx.doi.org/10.1021/acs.jpcb.6b02153) - [ picture\_as\_pdfGoldfain et al. - 2016 - ...](/sites/g/files/omnuum4256/files/manoharan/files/goldfain_et_al._-_2016_-_dynamic_measurements_of_the_position_orientation_and_dna_content_of_individual_unlabeled_bacteriophages.pdf) Rahmani, A. M.; Wang, A.; Manoharan, V. N.; Colosqui, C. E. [Colloidal Particle Adsorption at Liquid Interfaces: Capillary Driven Dynamics and Thermally Activated Kinetics](/publications/colloidal-particle-adsorption-liquid-interfaces-capillary-driven-dynamics-and). *Soft Matter* **2016**, *12* (30), 6365-6372. Rahmani, A. M.; Wang, A.; Manoharan, V. N.; Colosqui, C. E. [Colloidal Particle Adsorption at Liquid Interfaces: Capillary Driven Dynamics and Thermally Activated Kinetics](/publications/colloidal-particle-adsorption-liquid-interfaces-capillary-driven-dynamics-and). *Soft Matter* **2016**, *12* (30), 6365-6372. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dx.doi.org/10.1039/C6SM00966B) - [ picture\_as\_pdfRahmani et al. - 2016 - C...](/sites/g/files/omnuum4256/files/manoharan/files/rahmani-2016-colloidal_particle_adsorption_at_liquid_interfaces.pdf) The adsorption of single colloidal microparticles (0.5–1 μm radius) at a water–oil interface has been recently studied experimentally using digital holographic microscopy [Kaz et al., Nat. Mater., 2012, 11, 138–142]. An initially fast adsorption dynamics... - [ descriptionPublisher's Version](http://dx.doi.org/10.1039/C6SM00966B) - [ picture\_as\_pdfRahmani et al. - 2016 - C...](/sites/g/files/omnuum4256/files/manoharan/files/rahmani-2016-colloidal_particle_adsorption_at_liquid_interfaces.pdf) Wang, A.; McGorty, R.; Kaz, D. M.; Manoharan, V. N. [Contact-Line Pinning Controls How Quickly Colloidal Particles Equilibrate With Liquid Interfaces](/publications/contact-line-pinning-controls-how-quickly-colloidal-particles-equilibrate). *Soft Matter* **2016**, *12* (43), 8958-8967. Wang, A.; McGorty, R.; Kaz, D. M.; Manoharan, V. N. [Contact-Line Pinning Controls How Quickly Colloidal Particles Equilibrate With Liquid Interfaces](/publications/contact-line-pinning-controls-how-quickly-colloidal-particles-equilibrate). *Soft Matter* **2016**, *12* (43), 8958-8967. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dx.doi.org/10.1039/C6SM01690A) - [ picture\_as\_pdfWang et al. - 2016 - Cont...](/sites/g/files/omnuum4256/files/manoharan/files/wang_et_al._-_2016_-_contact-line_pinning_controls_how_quickly.pdf) Previous experiments have shown that spherical colloidal particles relax to equilibrium slowly after they adsorb to a liquid-liquid interface, despite the large interfacial energy gradient driving the adsorption. The slow relaxation has been explained in... - [ descriptionPublisher's Version](http://dx.doi.org/10.1039/C6SM01690A) - [ picture\_as\_pdfWang et al. - 2016 - Cont...](/sites/g/files/omnuum4256/files/manoharan/files/wang_et_al._-_2016_-_contact-line_pinning_controls_how_quickly.pdf) ### 2015 Perry, R. W. [Internal Dynamics of Equilibrium Colloidal Clusters](/publications/internal-dynamics-equilibrium-colloidal-clusters), 2015. Perry, R. W. [Internal Dynamics of Equilibrium Colloidal Clusters](/publications/internal-dynamics-equilibrium-colloidal-clusters), 2015. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dash.harvard.edu/handle/1/17465314) Colloidal clusters, aggregates of a few micrometer-sized spherical particles, are a model experimental system for understanding the physics of self-assembly and processes such as nucleation. Colloidal clusters are well suited for studies on these topics... - [ descriptionPublisher's Version](http://dash.harvard.edu/handle/1/17465314) ### 2014 Wang, A.; Dimiduk, T.; Fung, J.; Razavi, S.; Kretzschmar, I.; Chaudhary, K.; Manoharan, V. [Using the Discrete Dipole Approximation and Holographic Microscopy to Measure Rotational Dynamics of Non-Spherical Colloidal Particles](/publications/using-discrete-dipole-approximation-and-holographic-microscopy-measure-0). *Journal of Quantitative Spectroscopy and Radiative Transfer* **2014**, *146*, 499–509. Wang, A.; Dimiduk, T.; Fung, J.; Razavi, S.; Kretzschmar, I.; Chaudhary, K.; Manoharan, V. [Using the Discrete Dipole Approximation and Holographic Microscopy to Measure Rotational Dynamics of Non-Spherical Colloidal Particles](/publications/using-discrete-dipole-approximation-and-holographic-microscopy-measure-0). *Journal of Quantitative Spectroscopy and Radiative Transfer* **2014**, *146*, 499–509. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dx.doi.org/10.1016/j.jqsrt.2013.12.019) We present a new, high-speed technique to track the three-dimensional translation and rotation of non-spherical colloidal particles. We capture digital holograms of micrometer-scale silica rods and sub-micrometer-scale Janus particles freely diffusing in... - [ descriptionPublisher's Version](http://dx.doi.org/10.1016/j.jqsrt.2013.12.019) Dimiduk, T.; Perry, R.; Fung, J.; Manoharan, V. [Random-Subset Fitting of Digital Holograms for Fast Three-Dimensional Particle Tracking \[Invited\]](/publications/random-subset-fitting-digital-holograms-fast-three-dimensional-particle). *Applied Optics* **2014**, *53* (27), G177-G183. Dimiduk, T.; Perry, R.; Fung, J.; Manoharan, V. [Random-Subset Fitting of Digital Holograms for Fast Three-Dimensional Particle Tracking \[Invited\]](/publications/random-subset-fitting-digital-holograms-fast-three-dimensional-particle). *Applied Optics* **2014**, *53* (27), G177-G183. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dx.doi.org/10.1364/AO.53.00G177) Fitting scattering solutions to time series of digital holograms is a precise way to measure three-dimensional dynamics of microscale objects such as colloidal particles. However, this inverse-problem approach is computationally expensive. We show that... - [ descriptionPublisher's Version](http://dx.doi.org/10.1364/AO.53.00G177) ### 2013 Fung, J.; Manoharan, V. [ Holographic Measurements of Anisotropic Three-Dimensional Diffusion of Colloidal Clusters ](/publications/holographic-measurements-anisotropic-three-dimensional-diffusion-colloidal). *Physical Review E* **2013**, *88* (2), 020302. Fung, J.; Manoharan, V. [ Holographic Measurements of Anisotropic Three-Dimensional Diffusion of Colloidal Clusters ](/publications/holographic-measurements-anisotropic-three-dimensional-diffusion-colloidal). *Physical Review E* **2013**, *88* (2), 020302. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dx.doi.org/10.1103/PhysRevE.88.020302) We measure all nonzero elements of the three-dimensional diffusion tensor D for clusters of colloidal spheres to a precision of 1% or better using digital holographic microscopy. We study both dimers and triangular trimers of spheres, for which no... - [ descriptionPublisher's Version](http://dx.doi.org/10.1103/PhysRevE.88.020302) Fung, J. [Measuring the 3D Dynamics of Multiple Colloidal Particles With Digital Holographic Microscopy](/publications/measuring-3d-dynamics-multiple-colloidal-particles-digital-holographic), 2013. Fung, J. [Measuring the 3D Dynamics of Multiple Colloidal Particles With Digital Holographic Microscopy](/publications/measuring-3d-dynamics-multiple-colloidal-particles-digital-holographic), 2013. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dash.harvard.edu/bitstream/handle/1/11181215/Fung_gsas.harvard_0084L_11200.pdf) We discuss digital holographic microscopy (DHM), a 3D imaging technique capable of measuring the positions of micron-sized colloidal particles with nanometer precision and sub-millisecond temporal resolution. We use exact electromagnetic scattering... - [ descriptionPublisher's Version](http://dash.harvard.edu/bitstream/handle/1/11181215/Fung_gsas.harvard_0084L_11200.pdf) Wang, A.; Dimiduk, T.; Fung, J.; Razavi, S.; Kretzschmar, I.; Chaudhary, K.; Manoharan, V. [ Using the Discrete Dipole Approximation and Holographic Microscopy to Measure Rotational Dynamics of Non-Spherical Colloidal Particles ](/publications/using-discrete-dipole-approximation-and-holographic-microscopy-measure). *Journal of Quantitative Spectroscopy and Radiative Transfer* **2013**, *146*, 499–509. Wang, A.; Dimiduk, T.; Fung, J.; Razavi, S.; Kretzschmar, I.; Chaudhary, K.; Manoharan, V. [ Using the Discrete Dipole Approximation and Holographic Microscopy to Measure Rotational Dynamics of Non-Spherical Colloidal Particles ](/publications/using-discrete-dipole-approximation-and-holographic-microscopy-measure). *Journal of Quantitative Spectroscopy and Radiative Transfer* **2013**, *146*, 499–509. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dx.doi.org/10.1016/j.jqsrt.2013.12.019) We present a new, high-speed technique to track the three-dimensional translation and rotation of non-spherical colloidal particles. We capture digital holograms of micrometer-scale silica rods and sub-micrometer-scale Janus particles freely diffusing in... - [ descriptionPublisher's Version](http://dx.doi.org/10.1016/j.jqsrt.2013.12.019) ### 2012 Kaz, D.; McGorty, R.; Mani, M.; Brenner, M.; Manoharan, V. [ Physical Ageing of the Contact Line on Colloidal Particles at Liquid Interfaces ](/publications/physical-ageing-contact-line-colloidal-particles-liquid-interfaces). *Nature Materials* **2012**, *11* (2), 138-142. Kaz, D.; McGorty, R.; Mani, M.; Brenner, M.; Manoharan, V. [ Physical Ageing of the Contact Line on Colloidal Particles at Liquid Interfaces ](/publications/physical-ageing-contact-line-colloidal-particles-liquid-interfaces). *Nature Materials* **2012**, *11* (2), 138-142. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dx.doi.org/10.1038/nmat3190) Young’s law predicts that a colloidal sphere in equilibrium with a liquid interface will straddle the two fluids, its height above the interface defined by an equilibrium contact angle. This has been used to explain why colloids often bind to liquid... - [ descriptionPublisher's Version](http://dx.doi.org/10.1038/nmat3190) Fung, J.; Perry, R.; Dimiduk, T.; Manoharan, V. [ Imaging Multiple Colloidal Particles by Fitting Electromagnetic Scattering Solutions to Digital Holograms ](/publications/imaging-multiple-colloidal-particles-fitting-electromagnetic-scattering). *Journal of Quantitative Spectroscopy and Radiative Transfer* **2012**, *113* (18), 2482-2489. Fung, J.; Perry, R.; Dimiduk, T.; Manoharan, V. [ Imaging Multiple Colloidal Particles by Fitting Electromagnetic Scattering Solutions to Digital Holograms ](/publications/imaging-multiple-colloidal-particles-fitting-electromagnetic-scattering). *Journal of Quantitative Spectroscopy and Radiative Transfer* **2012**, *113* (18), 2482-2489. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dx.doi.org/10.1016/j.jqsrt.2012.06.007) Digital holographic microscopy is a fast three-dimensional (3D) imaging tool with many applications in soft matter physics. Recent studies have shown that electromagnetic scattering solutions can be fit to digital holograms to obtain the 3D positions of... - [ descriptionPublisher's Version](http://dx.doi.org/10.1016/j.jqsrt.2012.06.007) ### 2011 Fung, J.; Martin, E.; Perry, R.; Kaz, D.; McGorty, R.; Manoharan, V. [ Measuring Translational, Rotational, and Vibrational Dynamics in Colloids With Digital Holographic Microscopy ](/publications/measuring-translational-rotational-and-vibrational-dynamics-colloids-digital). *Optics Express* **2011**, *19* (9), 8051-8065. Fung, J.; Martin, E.; Perry, R.; Kaz, D.; McGorty, R.; Manoharan, V. [ Measuring Translational, Rotational, and Vibrational Dynamics in Colloids With Digital Holographic Microscopy ](/publications/measuring-translational-rotational-and-vibrational-dynamics-colloids-digital). *Optics Express* **2011**, *19* (9), 8051-8065. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dx.doi.org/10.1364/OE.19.008051) We discuss a new method for simultaneously probing translational, rotational, and vibrational dynamics in dilute colloidal suspensions using digital holographic microscopy (DHM). We record digital holograms of clusters of 1-μm-diameter colloidal spheres... - [ descriptionPublisher's Version](http://dx.doi.org/10.1364/OE.19.008051) Kaz, D. [ Colloidal Particles and Liquid Interfaces: A Spectrum of Interactions ](/publications/colloidal-particles-and-liquid-interfaces-spectrum-interactions), 2011. Kaz, D. [ Colloidal Particles and Liquid Interfaces: A Spectrum of Interactions ](/publications/colloidal-particles-and-liquid-interfaces-spectrum-interactions), 2011. - add\_circle\_outline do\_not\_disturb\_on Abstract Young's law predicts that a colloidal sphere in equilibrium with a liquid interface will straddle the two fluids, its height above the interface defined by an equilibrium contact angle. This equilibrium analysis has been used to explain why colloids often... McGorty, R. [ Colloidal Particles at Fluid Interfaces and the Interface of Colloidal Fluids ](/publications/colloidal-particles-fluid-interfaces-and-interface-colloidal-fluids), 2011. McGorty, R. [ Colloidal Particles at Fluid Interfaces and the Interface of Colloidal Fluids ](/publications/colloidal-particles-fluid-interfaces-and-interface-colloidal-fluids), 2011. - add\_circle\_outline do\_not\_disturb\_on Abstract Holographic microscopy is a unifying theme in the different projects discussed in this thesis. The technique allows one to observe microscopic objects, like colloids and droplets, in a three-dimensional (3D) volume. Unlike scanning 3D optical techniques... ### 2010 Dimiduk, T.; Kosheleva, E.; Kaz, D.; McGorty, R.; Gardel, E.; Manoharan, V. [A Simple, Inexpensive Holographic Microscope](/publications/simple-inexpensive-holographic-microscope). In *Digital Holography and Three-Dimensional Imaging 2010 (OSA Topical Meeting)*; Optical Society of America: Miami, FL, 2010; p. Paper JMA38. Dimiduk, T.; Kosheleva, E.; Kaz, D.; McGorty, R.; Gardel, E.; Manoharan, V. [A Simple, Inexpensive Holographic Microscope](/publications/simple-inexpensive-holographic-microscope). In *Digital Holography and Three-Dimensional Imaging 2010 (OSA Topical Meeting)*; Optical Society of America: Miami, FL, 2010; p. Paper JMA38. - add\_circle\_outline do\_not\_disturb\_on Abstract We have built a simple holographic microscope completely out of consumer components. We obtain at least 2.8 μm resolution and depth of field greater than 200 μm from an instrument costing less than $1000. Manoharan, V. [Digital Holographic Microscopy for 3D Imaging of Complex Fluids and Biological Systems](/publications/digital-holographic-microscopy-3d-imaging-complex-fluids-and-biological). *Frontiers of Engineering: Reports on Leading-edge Engineering from the 2009 Symposium*, 2010, 5-12. Manoharan, V. [Digital Holographic Microscopy for 3D Imaging of Complex Fluids and Biological Systems](/publications/digital-holographic-microscopy-3d-imaging-complex-fluids-and-biological). *Frontiers of Engineering: Reports on Leading-edge Engineering from the 2009 Symposium*, 2010, 5-12. - [ descriptionPublisher's Version](http://books.nap.edu/openbook.php?record_id=12821&page=5) - [ descriptionPublisher's Version](http://books.nap.edu/openbook.php?record_id=12821&page=5) ### 2008 McGorty, R.; Fung, J.; Kaz, D.; Ahn, S.; Manoharan, V. N. [Measuring Dynamics and Interactions of Colloidal Particles With Digital Holographic Microscopy](/publications/measuring-dynamics-and-interactions-colloidal-particles-digital-holographic). In *Digital Holography and Three-Dimensional Imaging Proceedings*; Optical Society of America Technical Digest (CD): St. Petersburg, Florida, 2008; Vol. paper DTuB1. McGorty, R.; Fung, J.; Kaz, D.; Ahn, S.; Manoharan, V. N. [Measuring Dynamics and Interactions of Colloidal Particles With Digital Holographic Microscopy](/publications/measuring-dynamics-and-interactions-colloidal-particles-digital-holographic). In *Digital Holography and Three-Dimensional Imaging Proceedings*; Optical Society of America Technical Digest (CD): St. Petersburg, Florida, 2008; Vol. paper DTuB1. - add\_circle\_outline do\_not\_disturb\_on Abstract - [ descriptionPublisher's Version](http://dx.doi.org/10.1364/DH.2008.DTuB1) - [ picture\_as\_pdfMcGorty et al. - 2008 - M...](/sites/g/files/omnuum4256/files/manoharan/files/mcgorty_et_al._-_2008_-_measuring_dynamics_and_interactions_of_colloidal_p.pdf) Micrometer-sized colloidal particles are a model system for understanding self-assembly in condensed matter. Here I present the results of digital holographic microscopy experiments that probe the 3D structure and dynamics of these systems. - [ descriptionPublisher's Version](http://dx.doi.org/10.1364/DH.2008.DTuB1) - [ picture\_as\_pdfMcGorty et al. - 2008 - M...](/sites/g/files/omnuum4256/files/manoharan/files/mcgorty_et_al._-_2008_-_measuring_dynamics_and_interactions_of_colloidal_p.pdf) ## Project team [### Ben Hafner ](/people/ben-hafner) Ben is an incoming PhD student in applied physics, currently working on in-line holographic microscopy of cyanobacteria. He loves Wikipedia rabbit holes, mechanical clocks, and outdoorsy stuff. ![Ben Hafner headshot](/sites/g/files/omnuum4256/files/styles/hwp_4_5__690x865/public/2025-09/ben.jpg?h=cc11cc1a&itok=KIUr8EZu) ## Alumni [### Anna Wang ](/people/anna-wang) PhD Applied Physics 2016 Anna was a PhD student in Applied Physics. She studied particle-interface interactions and self-assembly of particles with holography. Her work included high-speed, precise measurements of particle movement in 3D, and applying the knowledge to making... ![Anna Wang](/sites/g/files/omnuum4256/files/styles/hwp_4_5__690x865/public/manoharan/files/img_20150427_180756.jpg?itok=J3KoZtnR) [### Caroline Martin ](/people/caroline-martin-0) PhD Applied Physics 2024 Caroline was a PhD student in Applied Physics. She studied colloidal self-assembly by characterizing short-ranged interactions and designing DNA-mediated interactions. She has undergraduate degrees in physics and English, and spends her free time reading... ![Caroline](/sites/g/files/omnuum4256/files/styles/hwp_4_5__690x865/public/manoharan/files/screen_shot_2022-06-10_at_12.32.40_pm.png?itok=LrgcokaV) [### David M. Kaz ](/people/david-m-kaz)PhD Physics 2011 Dave was a PhD student in Physics who studied dynamic interactions between colloidal particles and liquid interfaces. He earned his PhD in 2011. ![Dave](/sites/g/files/omnuum4256/files/styles/hwp_4_5__690x865/public/manoharan/files/dave.jpg?itok=9ZEA4wFN) [### Ellen D. Klein ](/people/ellen-klein) PhD Physics 2019 Ellen Klein was a Ph.D. student in Physics who studied the self-assembly of colloidal clusters, with an emphasis on understanding what colloidal particles can tell us about entropy, phase transitions, and, possibly, biological systems. Ellen was a 2015... ![Headshot of Ellen Klein](/sites/g/files/omnuum4256/files/styles/hwp_4_5__690x865/public/manoharan/files/klein_photo.jpg?itok=jFJ8EXQw) [### Jennifer McGuire ](/people/jennifer-mcguire) PhD Applied Physics 2025 Jennifer was a PhD student in Applied Physics. She studied light transport through a variety of materials – including semiconductor nanowires, structurally colored colloidal assemblies, and grease films – using both computational and experimental... ![Jennifer McGuire](/sites/g/files/omnuum4256/files/styles/hwp_4_5__690x865/public/manoharan/files/jennifer_headshot.jpg?itok=quIuTFB_) [### Jerome Fung ](/people/jerome-fung)PhD Physics 2013 Jerome was a PhD student in Physics. His research involved characterizing and understanding the 3D dynamics of colloidal systems with holographic microscopy. He earned his PhD from Harvard in 2013. ![Jerome](/sites/g/files/omnuum4256/files/styles/hwp_4_5__690x865/public/manoharan/files/jerome_1.jpg?itok=1MIbyP9Z) See also:- [ Current research areas ](/research-areas/current-research-areas) - [ Holographic microscopy ](/research-areas/holographic-microscopy) - [ Project descriptions ](/page-categories/project-descriptions)