A5091423658- Advanced Optical Imaging Technologies
- Photorefractive and Nonlinear Optics
- Photonic and Optical Devices
- Liquid Crystal Research Advancements
- Virtual Reality Applications and Impacts
- Interactive and Immersive Displays
- Metamaterials and Metasurfaces Applications
- Digital Holography and Microscopy
- Optical Coatings and Gratings
- Semiconductor Lasers and Optical Devices
- Advanced optical system design
- Advanced Fiber Laser Technologies
- Advanced Antenna and Metasurface Technologies
- Advanced Vision and Imaging
- Augmented Reality Applications
- Photonic Crystals and Applications
- Phase-change materials and chalcogenides
- Advanced Materials and Mechanics
- Robotics and Sensor-Based Localization
- Plasmonic and Surface Plasmon Research
- Cancer Cells and Metastasis
- Occupational and environmental lung diseases
- Cancer, Hypoxia, and Metabolism
- Tactile and Sensory Interactions
- Quantum optics and atomic interactions
Pukyong National University
2024-2025
Samsung (South Korea)
2014-2023
Seoul National University
1998-2023
Jeonbuk National University
2022
Cornell University
2021
Samsung Advanced Institute of Technology (South Korea)
2002-2021
Bellingham Technical College
2020
California Institute of Technology
2017
Samsung (United States)
2017
Bumin Hospital Group
2014
Thin-film color reflectors inspired by Morpho butterflies are fabricated. Using a combination of directional deposition, silica microspheres with wide size distribution, and PDMS (polydimethylsiloxane) encasing, large, flexible reflector is created that actually provides better angle-independent characteristics than which can even be bent folded freely without losing its Morpho-mimetic photonic properties. Detailed facts importance to specialist readers published as "Supporting Information"....
Compact varifocal lenses are essential to various imaging and vision technologies. However, existing elements typically rely on mechanically actuated systems with limited tuning speeds scalability. Here, an ultrathin electrically controlled lens based a liquid crystal (LC) encapsulated dielectric metasurface is demonstrated. Enabled by the field-dependent LC anisotropy, applying voltage bias across cell modifies local phase response of silicon meta-atoms, in turn modifying metalens focal...
We report transmissive color filters based on subwavelength dielectric gratings that can replace conventional dye-based used in backside-illuminated CMOS image sensor (BSI CIS) technologies. The are patterned an 80 nm-thick poly silicon film a 115 SiO2 spacer layer. They optimized for operating at the primary RGB colors, exhibit peak transmittance of 60-80%, and have almost insensitive response over ± 20° angular range. This technology enables shrinking pixel sizes down to near micrometer.
Abstract Since its discovery almost 70 years ago, the hologram has been considered to reproduce most realistic three dimensional images without visual side effects. Holographic video extensively researched for commercialization, since Benton et al. at MIT Media Lab developed first holographic systems in 1990. However, commercially available displays have not introduced yet several reasons: narrow viewing angle, bulky optics and heavy computing power. Here we present an interactive slim-panel...
Broadband detection of mid-infrared (IR) photons extends to advanced optoelectronic applications such as imaging, sensing, and telecommunications. While graphene offers an attractive platform for broadband visible/IR photodetection, previous efforts improve its responsivity, example, by integrating light-absorbing colloids or waveguide antenna fabrication, were achieved at the cost reduced photon bandwidth. In this work, we demonstrate room-temperature operation a novel mid-IR photodetector...
Abstract An artificial muscle actuator resolves practical engineering problems in compact wearable devices, which are limited to conventional actuators such as electromagnetic actuators. Abstracting the fundamental advantages of an provides a small-scale, high-power actuating system with sensing capability for developing varifocal augmented reality glasses and naturally fit haptic gloves. Here, we design shape memory alloy-based lightweight actuator, so-called compliant amplified alloy...
Holography is one of the most prominent approaches to realize true-to-life reconstructions objects. However, owing limited resolution spatial light modulators compared static holograms, reconstructed objects exhibit various coherent properties, such as content-dependent defocus blur and interference-induced noise. The properties severely distort depth perception, core holographic displays 3D scenes beyond 2D displays. Here, we propose a hologram that imitates incoherent by engineering...
Abstract While recent research has shown that holographic displays can represent photorealistic 3D holograms in real time, the difficulty acquiring high-quality real-world limited realization of streaming systems. Incoherent cameras, which record under daylight conditions, are suitable candidates for acquisition, as they prevent safety issues associated with use lasers; however, these cameras hindered by severe noise due to optical imperfections such In this work, we develop a deep...
We propose an optical system for synthesizing double-phase complex computer-generated holograms using a phase-only spatial light modulator and phase grating filter. Two separated areas of the are optically superposed by 4-f configuration with optimally designed filter to synthesize arbitrary field distributions. The tolerances related misalignment factors analyzed, optimal synthesis method is described.
Abstract An augmented reality (AR) near-eye display using Pancharatnam-Berry (PB) phase lenses is proposed. PB provide different optical effects depending on the polarization state of incident light. By exploiting this characteristic, it possible to manufacture an AR combiner with a small form factor and large numerical aperture value. The adopted in proposed system operates as convex lens for right-handed circularly polarized light transparent glass left-handed merging screen, such...
A waveguide near-eye display (NED) with a dual-focal plane using polarization-dependent lens device is proposed. The novel optical composed of geometric phase holographic lens, wave plate, and circular polarizer, which operating as concave or see-through window, depending on the polarization state input beam. Such property ultra-thinness about 1.5 mm can be applied to combiner-eyepiece for augmented reality. This attached provides two depth planes multiplexing. We have demonstrated that our...
A simple liquid crystal display (LCD) backlight unit (BLU) comprising only a single-sheet polydimethylsiloxane (PDMS) light-guide plate (LGP) has been developed. The PDMS LGP, having micropatterns with an inverse-trapezoidal cross section, was fabricated by backside 3-D diffuser lithography followed PDMS-to-PDMS replication. BLU showed average luminance of 2878 cd/m2 73.3% uniformity when mounted in 5.08 cm module four side view 0.85 cd LEDs. developed can greatly reduce the cost and...
A novel LED backlight unit implementing a light guide plate (LGP) with two-dimensional array of grating micro-dots is proposed. By optimizing grating-vector orientations local gratings and applying suitable grating-depth modulation in the array, taking into consideration radiation pattern source, uniform out-coupled distribution within narrow luminance angle was achieved without recognizable hot spots. Such fabricated using dot-matrix holographic interferometer setup UV embossing...
Hypoxia is a hallmark of the solid tumor microenvironment and associated with poor outcomes in cancer patients. The present study was performed to investigate mechanisms underlying hypoxia-induced phenotypic changes using human malignant mesothelioma (HMM) cells. Hypoxic conditions were achieved by incubating HMM cells air chamber. effect hypoxia on phenotype investigated performing vitro clonogenicity, drug resistance, migration, invasion assays. Signaling pathways molecules involved more...
Many contemporary imaging systems seek tunable focusing components with minimal form factors and versatile functionalities; however, existing solutions are typically limited in size, efficiency, tuning speed. Here, low-loss all-dielectric metasurfaces integrated liquid crystals (LCs) used to demonstrate highly compact multifunctional zoom components. The phase profiles imparted by the metalens modulated real time means of field-dependent LCs, enabling electrically driven continuous focal...
We propose a hogel overlapping method for the holographic printer to enhance lateral resolution of stereograms. The size is directly related stereogram. Our analysis by computer simulation shows that there limit decreasing while printing Instead reducing hogel, stereograms can be enhanced overlapped hogels, which makes it possible take advantage multiplexing property volume hologram. built printer, and recorded two using conventional proposed methods. images movies experimentally captured...
In this paper, we present the world's first single-chip field-programmable gate array holographic video processor. It makes 16 computer-generated color holograms of resolution 1920 × 1080 in a second. uses an off-the-shelf commercial liquid crystral display for spatial light modulator. To build processor, used layer-based hologram (CGH) algorithm and hardware efficient CGH architecture using fixed-point arithmetic. The processor provides moving with low cost, small footprint, high energy...
Recent studies have shown that cascade cost volume can play a vital role in deep stereo matching to achieve high resolution depth map with efficient hardware usage. However, how construct good as well effective sampling for them are still under in-depth study. Previous cascade-based methods usually perform uniform predicted disparity range based on variance, which easily misses the ground truth and decreases accuracy. In this paper, we propose an uncertainty adaptive network (UASNet)...
We propose augmented reality (AR) near-eye display using a holographically printed freeform mirror array. A wide depth of field AR system is implemented by the retinal projection via small Since we use holographic array, more advantages over traditional physical array are achieved. Due to see-through characteristics optical element (HOE), structure does not obstruct sight an observer. Also, printing technique for enables without floating lens and compensates astigmatism HOE. The detailed...
A compact augmented reality (AR) combiner using Pancharatnam-Berry phase (PBP) lens and holographic optical element (HOE) is proposed. PBP activated as a convex or concave according to the polarization state of input light wave. By this characteristic, thin AR eyepiece with large numerical aperture (NA) constructed. The operates for right-handed circular transparent plate left-handed circularly polarized light. In order adopt combiner, chromatic aberration should be compensated. To resolve...
A slim beam deflector that satisfies both a large steering angle and area can be very useful in various applications. However, smaller electrode pitch for enlargement of its are trade-off relations due to the limited number control channels an electrically tunable system. For active where actual diffraction occurs, indium tin oxide 2 µm was implemented through stepper lithography. The via-hole process developed expand reduced small pitch. We with 7200 controllable 14.4mm×14.4mm. maximum is...
Holography has been considered as the ultimate technology for three-dimensional visual experience. Compared to well-established static holographic technology, video display is still in research and development stage, before commercial products. This paper reviews various kinds of researches related systems from beginning recent improvements, compares each specification, describes their features. We discuss key requirements be commercialized widely used everyday life.
Highly efficient transmission-type beam deflectors that have high angular resolution been widely used for various applications. Continuously tunable also needed many purposes. An indium-tin-oxide (ITO), transparent electrodes, was placed on the upper and lower glass substrate. The ITO layer substrate patterned by contact mask aligner relatively wide input output pad compared to main grating patterns in active area. These pads are connected each driving integrated circuit (IC), which has 360...