Research Updates Archive

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Archived Research Updates

3-D Visualization and Imaging Systems Laboratory

Date Published: November 20, 2014

Hong Hua's 3-D Visualization and Imaging Systems Laboratory specializes in a wide variety of optical technologies enabling advanced 3-D displays, 3-D visualization systems and collaborative immersive virtual and augmented environments, and novel imaging systems for medicine and surveillance applications. The 3DVIS Lab also uses 3-D displays to better understand human visual perception and visual artifacts and investigates design principles for effective human-computer interface in augmented environments.

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Demonstration of realistic cues for 3-D displays.

Accuracy of the Skin Depth Correction for Metallic Nanoparticle Polarizability

Date Published: June 20, 2019

The McLeod lab's research shows that light scattering and optical trapping calculations based on the full volume of nanoparticles is more accurate than calculations based on only the skin depth. This study suggests that a simpler model is more accurate than the skin depth model, which had been widely used by researchers for the past three decades. Read the published article.

 

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Simulation geometry. (a) Far field scattering calculations are performed for solid and hollow gold nanospheres illuminated by plane waves. (b) Optical force calculations are performed on gold nanospheres displaced laterally by Δx from the optical axis of a Gaussian beam with λ/2 beam waist.

Aspheric Metrology Laboratory

Date Published: November 20, 2014

The Aspheric Metrology Laboratory headed by John E. Greivenkamp designs and builds advanced interferometric systems for metrology and optical testing. Research interests include ophthalmic and visual optics, ophthalmic instrumentation and measurements, interferometry and optical testing of aspheric and freeform surfaces, optical fabrication, optical system design, optical metrology systems, distance measurement systems, sampled imaging theory, and optics of electronic imaging systems.

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Left: Partial view of instrument for acquiring corneal topography. Right: Interferogram of a test sample.

Effects of Ray Position Sampling on the Visual Responses of 3D Light Field Displays

Date Published: May 7, 2019

This study, out of the Hong Hua laboratory, investigates the effects of light ray sampling on the quality of the rendered focus cues and the visual responses of a viewer in light field displays. Accounting for both the specifications of a light field display system and the ocular factors of the human visual system the researchers systematically model and analyze the ray position sampling issue in the reconstruction of the light field. This characterizes the effect on the quality of the rendered retinal image and on the accommodative response in viewing a 3D light field display. Using a recently developed 3D light field display prototype, Hua's lab further validates the effects of ray position sampling on the resolution and accommodative response of a light field display that matches with theoretical characterizations.

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Schematic illustration and results of ray trace based on setup which has (a) infinitely high pixel resolution and (b) limited pixel resolution of the CDP. Not to scale. 

Gmitro Lab

Date Published: November 24, 2014

Optical imaging techniques are now frequently employed for medical diagnosis. A familiar example is biopsy, where a pathologist observes an excised tissue sample under an optical microscope to diagnose a disease. The discipline of optical biopsy takes an optical instrument (e.g., a confocal microscope) in a miniaturized endoscopic form directly to the tissue in need of evaluation. Optical biopsy allows real-time in situ analysis with greater ease and, potentially, increased accuracy. Arthur Gmitro’s research group has pioneered the development of fiber-bundle-based fluorescence confocal microendoscopy, building systems to image a variety of endoscopically and/or laparoscopically accessible organ sites. The instrument shown in the figure at above left is being clinically evaluated for its ability to identify early-stage ovarian and fallopian tube cancers.

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Left: Confocal microendoscope imaging probe in contact with an ovary surface during a laparoscopic procedure. Right: Fluorescence image obtained from the probe showing individual nuclei of cells on the epithelial ovary surface.

High-performance integral-imaging-based light field augmented reality display using freeform optics

Date Published: May 7, 2019

Hong Hua's 3-D Visualization and Imaging Systems Laboratory has developed a new integral-imaging-based light field augmented-reality display. This achieves a wide see-through view and high image quality over a large depth range using custom-designed freeform optics and a tunable lens and aperature array. This research creates a compact design for a head-mounted-display that offers a true 3D display. 

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(a) The image of bench-top prototype with a quarter coin; (b) the 3D model of the binocular system worn on human head; and (c) the photograph of an integrated binocular prototype.

(a) The image of bench-top prototype with a quarter coin; (b) the 3D model of the binocular system worn on human head; and (c) the photograph of an integrated binocular prototype.

Image Science Laboratory

Date Published: November 24, 2014

Matthew A. Kupinski's Image Science Laboratory explores concepts in objective image quality assessment and applies them to diverse areas, including diffuse-optical imaging, clinical CT imaging and national security arenas. His team has developed novel models of imaging systems that make the most efficient use of scattered light, combining task-based imaging with radiative-transport models of light propagation to allow all acquired data to be used when performing a scientifically relevant task. In addition, the Image Science Lab has applied task-based measures of image quality to homeland security imaging, wherein large-scale imaging devices search for sources of radiation in urban environments. These promising techniques have led to collaboration with Sandia National Laboratories and the U.S. Department of Energy on the development of imaging systems for confirming nuclear-treaty disarmament. In addition, Kupinski’s group has worked with a number of commercial system manufacturers to bring image-science concepts out of the university environment and into the commercial realm.

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The AdaptiSPECT small-animal imaging system to be used in pre-clinical studies of cancer treatments, drug delivery, and new imaging agents. Aperture, cameras, and bed position are fully adaptive and respond to the data being obtained to ensure that task performance is maximized. (Work of Cecile Chaix)

Imaging and Applied Optics Laboratory

Date Published: November 20, 2014

The research in Imaging and Applied Optics Laboratory specializes in optical engineering and biomedical optical imaging. In the field of optical engineering we focus on (1) optical system development from design, to fabrication and to testing, (2) freeform optics, (3) optical metrology and 3D imaging, (4) computational imaging, and (5) advanced imaging technologies. In biomedical optical imaging, we concentrate on (1) novel optical imaging techniques and devices for clinical applications, and (2) advanced biomedical optical imaging techniques and device for biomedical research. 

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Far left: Image-guided surgical system. Right: Images of subcutaneous breast cancer mouse model.

Far left: Image-guided surgical system. Right: Images of subcutaneous breast cancer mouse model.

Little Sensor Lab

Date Published: September 26, 2017

Judith Su's lab centers on label‐free single molecule detection using microtoroid optical resonators. The technique called FLOWER (Frequency Locked Optical Whispering Evanescent Resonator) uses frequency locking in combination with balanced detection and data processing techniques to achieve single molecule sensitivity and fast detection times.

The lab's main focus is on basic research, and translational medicine through the development of miniature field portable devices as a tool to detect, understand, control, and treat various diseases. The lab is also developing chemical sensors for environmental monitoring, reducing threats, assisting national defense, and enabling clean sport competition.

 

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Microtoroid optical resonator

LOFT Develops Instantaneous Phase-Shifting Deflectometry Technology

Date Published: September 21, 2017

The Large Optics Fabrication and Testing (LOFT) group under the lead of Dae Wook Kim has developed a new instantaneous deflectometry technology, which they implemented on an iPhone (see Trumper, Choi, and Kim, “Instantaneous Phase Shifting Deflectometry,” Optics Express 2017). This development enables high precision snapshot measurements of time-varying surfaces, such as a deformable mirror (example in figure) or active bending modes of a large optic. Phase shifting deflectometry now has the capability to measure dynamic optics.

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Deformable mirror (DM) test configuration using the iPhone. Rays drawn in red arrows represent the time-reversed paths to show the as-used section of the screen. 

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Deformable mirror surface measurement made at ~10 Hz using instantaneous deflectometry implemented on an iPhone. 

LOFT Develops Simultaneous Multi-Segmented Mirror Orientation Test System

Date Published: September 21, 2017

The Large Optics Fabrication and Test (LOFT group PI: Dae Wook Kim) group developed the Simultaneous Multi-segmented mirror Orientation Test System for segmented optics application (H. Choi, I. Trumper, M. Dubin, W. Zhao, and D. W. Kim, Opt. Express 25, 18152-18164 (2017).) The localized 2D sinusoidal patterns are displayed on the screen and the CMOS camera captures the images reflected from each segment. Due to its high computing efficiency and accuracy (15 Hz, 0.8 µrad), it allows a dynamic monitoring and controlling of a multi-segmented optics system or a closed-loop optical system with a long-term stability requirement.

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Simultaneous Multi-segmented mirror Orientation Test System

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Milster Lab

Date Published: November 20, 2014

Tom D. Milster's research aims to "push the boundaries of optical science and engineering to produce the maximum amount of information from a given volume of space and time." His group designs, simulates and fabricates custom computer-generated holograms, Diffractive Optical Elements, phase structures and amplitude masks. They investigate hyper-numerical-aperture linear and nonlinear microscopy, where the NA is greater than 1.5 and evanescent waves provide resolution well beyond conventional microscope limits. They are also interested in the development of "freeform" holography, with DOEs adding function and utility to 3-D structures. Unique instruments in the lab include a vacuum-ultraviolet microscope at the 121.6-nanometer wavelength and a high-resolution infrared microscope for determining subcellular metabolism. Research applications include industrial inspection, graphene characterization, metamaterial testing, data storage, lithography, and bio-film and subcellular imaging.

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Left: Lithography tool. Right: Measurement of micro-optical structure fabricated by Milster lab.

 

New Laser Beam Steering Technology for LIDARs

Date Published: June 5, 2018

recent publication from the Takashima Lab on LIDAR is ranked as the 7th of the most downloaded papers in Optics Express in April 2018. The research team demonstrated a LIDAR system which remotely identifies location and distance of moving objects with a high sampling rate of 3.4K points/s. The new laser beam steering concept is expected to replace a bulky and slow scanning LIDAR system with a fast and light-weight one that can be a mass-produced Micro Electro Mechanical System (MEMS) device.

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The LIDAR system measures the position of a moving object.

An example of how the LIDAR system measures the position of a moving object suspended from the ceiling.

Ophthalmic and Visual Optics Laboratory

Date Published: November 20, 2014

The Ophthalmic and Visual Optics Laboratory led by Jim Schwiegerling designs and fabricates instrumentation for assessing various properties of the human eye. These devices include wavefront sensors for measuring aberrations of the eye and topographers for measuring the three-dimensional geometry of the corneal surface. The lab has developed novel retinal imaging techniques incorporating both polarimetric and spectroscopic measurement of the retinal tissue. Schwiegerling’s group is also expanding usage of these core technologies to address needs in the fields of optical design and testing, biometric identification and computational photography.

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Specialized screen for visual assessment.

Optical Design Laboratory

Date Published: November 20, 2014

José Sasián's Optical Design Laboratory conducts research in optical design, including imaging and nonimaging systems; optical aberration theory and novel methods for aberration correction; illumination optics; aspheric surfaces; optical testing methods and modeling; optomechanics; optics for lithography; microscope design; optics for visual systems; light in gemstones; and modeling light propagation in optical systems.

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Lens design of wide-field and hyper-high-numerical-aperture projection system.

Optical Physics Group

Date Published: November 24, 2014

Masud Mansuripur's Optical Physics Group researches optical-magnetic-macromolecular data storage, light-matter interaction, magneto-optical effects and the mechanical effects of light involving the exchange of linear and angular momenta between electromagnetic fields and material media.

As an example of the latter effects, the figure above shows a hollow metallic cone with an apex angle of 90 degrees, illuminated by a circularly polarized light beam. Upon reflection from the cone, the spin angular momentum of the beam is reversed. However, no angular momentum is transferred to the cone, because the reflected beam picks up an orbital angular momentum twice as large but opposite in direction to that of its spin. The figure also shows profiles of the phase and the Poynting vector in the cross-sectional plane of the reflected beam.

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Light reflected from a hollow cone undergoing changes in spin and orbital angular momentum, as shown by the variation of the Poynting vector and phase in transverse plane. 

Polarization Laboratory

Date Published: November 24, 2014

The polarization of scattered or reflected light from an object carries information about its material characteristics. Russell A. Chipman’s Polarization Laboratory specializes in developing precision polarimeters that measure from the ultraviolet to the short-wave infrared. When configured as imaging devices, these polarimeters can produce research-grade spatial and angular resolution for sample characterization. With polarimetric accuracy of 0.1 percent, the instruments are ideal for precise optical characterization, such as measuring the concentration and distribution of aerosols in the atmosphere.

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AirMSPI image showing surface features that show up preferentially in the degree of linear polarization image.

Quantum Gases Group

Date Published: November 24, 2014

Brian P. Anderson's Quantum Gases Group uses laser light to cool gases of rubidium atoms to a few billionths of a degree above absolute zero. These atomic fluid droplets, called Bose-Einstein condensates, follow the laws of quantum physics and serve as valuable tools for exploring fundamental physics topics such as quantum turbulence, the primary concern of the Anderson group. BEC turbulence is indicated by the motion of vortices, microscopic holes that identify fluid circulation like the eyes of tiny hurricanes. New regimes of quantum fluid dynamics and quantum turbulence can be discovered by watching how these vortices move and interact.

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Vortices showing quantum turbulence in a BEC.

Quantum Information and Control Group

Date Published: November 24, 2014

Poul Jessen's Quantum Information and Control Group investigates fundamental problems in quantum information science using ultracold atoms. One project uses Zeeman sublevels in the electronic ground state of atomic cesium to explore computer-optimized quantum control, quantum tomography and quantum chaos. A second project creates many-atom spin-squeezed states through quantum measurement back-action, with the long-term goal of improving quantum-limited atomic clocks and sensors. A third project traps atoms in the evanescent field around an optical nanofiber, with the aim of developing an atom-light quantum interface.

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Experiment for production and quantum control of ultracold atoms.

Soft Nano-Photonic Systems

Date Published: June 27, 2016

Nano-photonics is the study of how light interacts with objects smaller than its wavelength. It forms the basis of some of the last decade’s revolutionary progress in photonics such as super-resolution imaging, optical cloaking, and optical biosensing. While nano-photonic devices are most often implemented in hard materials using semiconductor-processing methods, these approaches can be limited in compatibility with biological materials or complex three-dimensional designs.

Assistant Professor Euan McLeod is working on developing novel nano-photonic systems from building blocks dispersed in soft colloidal materials. This approach is compatible with biological systems, and can be harnessed to fabricate three-dimensional structures. Current application areas of interest include microscopic bio-imaging, biomedical sensors, and photonic metamaterials.

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Optical tweezer apparatus for colloidal nanoparticle manipulation.

Takashima Laboratory

Date Published: November 20, 2014

Yuzuru Takashima's laboratory constructs innovative optical devices through a wide spectrum of optical science and engineering techniques. Research topics include the design and fabrication of nanophotonic devices, micro-optics, network-based optical input-output devices, and optical and holographic information storage. Among additional areas of interest are X-ray phase contrast imaging, ultrawide field-of-view imaging, micromirror fabrication, CMOS-compatible packaging for silicon photonics and heads-up displays for mobile applications.

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The Takashima Lab is currently working on Digital Holographic Data Storage, Imaging and Long-Range LIDAR, Near to Eye Displays, Photonic Channeled X-Ray Detetector Arrays, Free-Space Optical Communications, Ray Aberration Generators and Micro-Vertical Light Couplers.

Theoretical and Computational Optical Physics Group

Date Published: November 24, 2014

The Theoretical and Computational Optical Physics Group led by Miroslav Kolesik explores the intersection of modern nonlinear optics, atomic and molecular physics, and strong-field phenomena. Research interests span statistical mechanics, Monte Carlo simulation, critical phenomena, nonequilibrium and driven systems, semiconductor laser simulation and optics; current activity concentrates on computational optics, particularly ultrashort optical pulse interactions.

Recent work includes first-principle methods to describe light-matter interactions in regimes that defy the tools and notions of traditional nonlinear optics and that scale from the quantum through the optical to the macroscopic. The challenge is in the integration of the microscopic medium description into space- and time-resolved, realistic simulations of experiments. Substantial research is being done in close collaboration with teams in the U.S. and Europe.

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 Resonant-state landscape of a quantum system: It allows economic, yet accurate calculation of nonlinear optical properties.

Theoretical-Computational Optical Physics and Applied Mathematics Group

Date Published: November 24, 2014

The Theoretical-Computational Optical Physics and Applied Mathematics Group led by Jerome V. Moloney studies ultrashort laser pulse interaction with gases and condensed media under extreme conditions. Extreme intensities acting over tens to hundreds of femtoseconds strip and accelerate electrons from an atom, creating anisotropic distributions of electrons and ions that eventually equilibrate to form a plasma channel. This channel acts like an extended conducting wire and can direct high-voltage charges and, potentially, lightning strikes. Accompanying this explosive event is the creation of a white light super-continuum source that can be used to perform remote spectroscopy and detect atmospheric molecules and pollutants at multikilometer ranges.

 

In another activity, Moloney's team is designing new classes of high-power ultrashort-pulsed semiconductor disk lasers using first principles quantum many-body theory, processing these into laser devices and demonstrating them in the laboratory.

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Electromagnetic light bullet transports multiple Terawatts of power over hundreds of meters in the atmosphere. Bottom: Snapshots of the bullet at fixed locations along its path. The bullet itself has intensity spikes (in red) and sheds higher harmonic radiation packets in its wake (to its left).

 

Ultrafast Lasers Group

Date Published: November 24, 2014

The Ultrafast Lasers Group headed by R. Jason Jones employs novel light sources, such as the femtosecond frequency comb generated by a phase-stabilized train of ultrashort pulses, for experimental ultrafast optical science and precision laser spectroscopy. Such sources have enabled studies of temporal dynamics in light-matter interactions ranging from attosecond to several-second time scales, leading to the development of new atomic clocks and subfemtosecond timing.

Current activities include precision spectroscopy of laser-cooled mercury and the development of frequency comb sources in the extreme-ultraviolet based on intracavity high-harmonic generation.

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 Ionization of xenon during intracavity high-harmonic generation.

 ARPA-E MOSAIC Program

Date Published: July 26, 2016

Professor Robert A. Norwood's research portfolio consists of work ranging from nanoscale electro-optic modulators to 40 square meter hybrid solar energy systems. A common theme that cuts across this 10 order of magnitude change in length scale is the coupling of fundamental optical materials and device physics to emerging applications with significant impact. The Photonic Materials and Device Lab (PMDL) is constantly seeking out new optical materials and photonic device innovations that can impact a broad range of applications, ranging from information technology to renewable energy, to infrared optics.  

The ARPA-E MOSAIC program is focused on creating more efficient (> 30%) solar panels by combining standard silicon panels for diffuse light collection (labeled as 1-Sun sheet in the figure below) and high efficiency concentrated photovoltaic arrays for the direct sunlight (know as direct normal insolation or DNI).  Key optical design elements include a cylindrical lens concentrator in one direction and a waveguide sheet concentrator in the other direction as shown in the schematic.  This work is also done under subcontract to Sharp Laboratories of America and started in January 2016.   

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Schematic showing basic approach to a high efficiency solar panel.