Research Updates Archive

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.

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.

A recent publication from the Takashima Lab on all-MEMS (Micro Electro Mechanical System) LIDAR address a quasi-solid-state lidar system employing Texas Instruments Digital Micromirror Device (DMD) and 2-dimensional MEMS mirror for lidar transmitter and a 2nd DMD for receiver.

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.

The fabrication of three-dimensional (3D) microscale structures is critical for many applications, including strong and lightweight material development, medical device fabrication, microrobotics, and photonic applications. While 3D microfabrication has seen progress over the past decades, complex multicomponent integration with small or hierarchical feature sizes is still a challenge. Dr. Jeffrey Melzer and Dr. Euan McLeod have precisely fabricated 3D microstructures from two types of micron-scale building blocks linked by biochemical interactions using an optical positioning and linking (OPAL) platform based on optical tweezers technology.

Nuclear imaging modalities, such as positron emission tomography and single-photon emission computed tomography, form an important element of modern medical diagnostics. The University of Arizona Center for Gamma-Ray Imaging, led by Harrison H. Barrett in cooperation with Lars R. Furenlid, Matthew A. Kupinski and Eric W. Clarkson, focuses on advancing the state of the art in radionuclide imaging (e.g., PET and SPECT). The CGRI uniquely combines rigorous theory, inventive computational tools, advanced detectors and electronics, innovative imaging systems, novel radiotracers and cutting-edge clinical and preclinical applications. This work is done within the context of gamma-ray imaging, but it is important to other forms of medical imaging and image science in general.

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.

A recent publication from Takashima Lab., “Gigapixel and 1440-perspective extended-angle display by megapixel MEMS-SLM” demonstrates a drastic increase in pixel counts of a display device for AR/VR and lidar application. A novel time multiplexed and pulsed illumination method effectively squeezed giga-pixel (109 pixels) output from a commercially available mega-pixel (106 pixels) display device while routing image into different directions.

Researchers at the Wyant College of Optical Sciences (OSC) are helping to build what Daewook Kim, Ph.D., an OSC professor who specializes in optical engineering science, calls the “telescope of the future.” “We are trying to redefine what we can do on the ground in terms of looking at space,” Dr. Kim said. Intended to be one of the most powerful telescopes on Earth, the Giant Magellan Telescope (GMT) will have a primary mirror 24 meters across, and it will be about 100 times more powerful in terms of light collection capability and enable 10 times higher imaging resolution than the Hubble Space Telescope. 

Optical polymer-based integrated photonic devices are gaining interest for
applications in optical packaging, biosensing, and augmented/virtual reality
(AR/VR). The low refractive index of conventional organic polymers has
been a barrier to realizing dense, low footprint photonic devices. The fabrication and characterization of integrated photonic devices using a new class of high refractive index polymers, chalcogenide hybrid inorganic/organic
polymers (CHIPs), which possess high refractive indices and lower optical
losses compared to traditional hydrocarbon-based polymers, are reported.

3D printing of optics has gained significant attention in optical industry, but most of the research has been focused on organic polymers. In spite of recent progress in 3D printing glass, 3D printing of precision glass optics for imaging applications still faces challenges from shrinkage during printing and thermal processing, and from inadequate surface shape and quality to meet the requirements for imaging applications. This paper reports a new liquid silica resin (LSR) with higher curing speed, better mechanical properties, lower sintering temperature, and reduced shrinkage, as well as the printing process for high-precision glass optics for imaging applications.

The fabrication of three-dimensional (3D) microscale structures is critical for many applications, including strong and lightweight material development, medical device fabrication, microrobotics, and photonic applications. While 3D microfabrication has seen progress over the past decades, complex multicomponent integration with small or hierarchical feature sizes is still a challenge. Dr. Jeffrey Melzer and Dr. Euan McLeod have precisely fabricated 3D microstructures from two types of micron-scale building blocks linked by biochemical interactions using an optical positioning and linking (OPAL) platform based on optical tweezers technology.

Dr. Pierre-Alexandre Blanche and OSC alumnus, Craig Draper, present optical ray tracing as well as an experimental prototype of a curved waveguide combiner with pupil expansion for augmented reality (AR) and mixed reality (MR) glasses. The curved waveguide combiner takes advantage of holographic optical elements both for injection and extraction of the image to correct the aberrations introduced during the propagation of light inside the waveguide.

At the Wyant College of Optical Sciences’s Little Sensor Lab, researchers are building sensors that have three key advantages: They can detect low concentrations of substances, provide results in 30 seconds or less, and they don’t need to label or amplify the substance they’re trying to detect. But perhaps the best part? They may be helpful in detecting and treating COVID-19, cancer and scores of other harmful or deadly contaminants.

As imaging devices — from smartphones to military drones to security cameras to cars — become ubiquitous, rising data volume and processing demands become problematic. Compression is routinely employed to reduce image file sizes for convenient storage and transmission. However, the success of image compression techniques suggests that traditional imaging systems can be highly inefficient, collecting redundant data that could be compressed without significant degradation. The field of compressive imaging addresses this shortcoming by acquiring a “compressed image” directly in the optical domain.

A recent paper was published in the APS Physical Review A by the Guha lab, associated with the Center for Quantum Networks, and was selected as an Editor's Suggestion. The work was funded on the NSF Convergence Accelerator program in collaboration with University of Maryland. The paper discusses trapped-ion based quantum repeaters and was led by Wyant College Ph.D. student, Prajit Dhara, advised by Dr. Saikat Guha and co-advised by Dr. Kaushik Seshadreesan, Assistant Professor at Univ. of Pittsburg.

The Wright research group presents experimental evidence of photon droplets in an attractive (focusing) nonlocal nonlinear medium. Photon droplets are self-bound, finite-sized states of light that are robust to size and shape perturbations due to a balance of competing attractive and repulsive forces. Theoretically the self-bound state arises due to competition between the s-wave and d-wave nolinear terms, along with diffraction. This research presents numerics and experiments supporting the existence of photon droplet states and measurements of the dynamical evolution of the photon droplet orbital angular momentum.

The Optica Publishing Group highlighted a paper published by a team of researchers at UArizona with industry partners, Nikon and L'Garde, for the "Spotlight on Optics" feature. The team includes students from the labs of Profs. Daewook Kim, Yuzuru Takashima, and Chris Walker at Steward Observatory.  The paper “Modeling and Characterization of OASIS Inflatable Primary Antenna by Dual Modality Metrology” discusses the concept of a 14m aperture inflatable space observatory and its feasibility study focusing on the primary inflatable mirror. The antennas are innovative because they are not rigid but consist of two membranes that bend under the pressure exerted by a gas introduced between them.​​​​​ ​ The new approach to space telescopes could lower the cost of astronomical satellites and lead the way for the future of large, space-based inflatable antennas.

Periodicity of the Computer Generated Holograms (CGHs) for beam steering makes it possible to utilize the Talbot self-phase-image of the CGH to enhance the diffraction efficiency in the infrared domain. The architecture doubles phase modulation by a factor of two, which enables using TI-PLM designed for visible wavelength for infrared laser beam steering for lidar applications.

The research group of Ewan Wright has recently found applications in the simulation of a variety of physical phenomena such as superfluidity, vortex instabilities, and artificial gauge theories. This research presents the new opportunity for a room-temperature photon superfluid which can mimic the geometry of a rotating acoustic black hole. This allows the researchers to measure the local flow velocity and speed of waves in the photo superfluid.

Using a slip aperature and diffraction grating on a smartphone, the research team, including Dongkyun "DK" Kang, has developed a confocal microscope. It's use for in vivo human skin imaging was successful, conducting two-dimensional confocal imaging without the need for any beam scanning devices. These results suggest that the smartphone confocal microscope has a potential to be a low-cost option capable of examining cellular details in vivo and may help disease diagnosis in resource-poor settings, where conducting standard histopathological analysis is challenging. 

A new paper in Optics Express Vol. 30, Issue 2 features the work of Chengyu Wang, Minghao Hu, Yuzuru Takashima, Timothy J. Schulz, and David J. Brady. The team uses convolutional neural networks to recover images optically down-sampled by 6.7 × using coherent aperture synthesis over a 16 camera array. Where conventional ptychography relies on scanning and oversampling, here the researchers apply decompressive neural estimation to recover full resolution image from a single snapshot, although as shown in simulation multiple snapshots can be used to improve signal-to-noise ratio (SNR).

A recent publication from Takashima Lab on LIDAR is address laser beam steering by motion-less and solid-state MEMS (Micro Electro Mechanical System) device, Texas Instruments Phase Light Modulator (TI-PLM). The research team demonstrated a quasi-continuous and multi-points beam steering by TI-PLM.

Simple patterns, such as stripes, can be created from instabilities that involve linear momentum states of waves. The group of Professor Rolf Binder recently asked the question whether similar instabilities and patterns involving orbital angular (instead of linear) momentum states are possible. They performed theoretical investigations of polaritonic quantum fluids. Details about their findings are in Phys. Rev. Lett. 119, 113903 (2017). 

The Theoretical Optical Physics Group headed by Ewan M. Wright conducts research across a broad area including ultrashort nonlinear pulse propagation in transparent media, Vertical External Cavity Semiconductor Lasers (VECSELs), nonlinear optics of photon fluids, and optical binding of particles. In each case the goal is to develop the underlying theory for each area in tandem with the simulation capability for existing or potential experiments.

The Theoretical Solid-State Optics Group led by Rolf Binder focuses on the optical properties of semiconductor structures. Using microscopic quantum-mechanical many-body theories, including nonequilibrium Green's functions, the group pursues projects ranging from basic physical studies to application-oriented simulations. Recent and ongoing examples include slow- and fast-light effects in bulk semiconductors and semiconductor heterostructures, optical refrigeration of semiconductors, optical and elastic properties of semiconductor nanomembranes, optical properties of graphene, and pattern formation and control in quantum fluids realized by exciton polaritons in semiconductor microcavities.