A5100343631- Photonic and Optical Devices
- Semiconductor Lasers and Optical Devices
- Plasmonic and Surface Plasmon Research
- Advanced Fiber Optic Sensors
- Advanced Fiber Laser Technologies
- Radio Frequency Integrated Circuit Design
- Advanced Power Amplifier Design
- Photorefractive and Nonlinear Optics
- Photonic Crystals and Applications
- 3D IC and TSV technologies
- Nonlinear Optical Materials Research
- Advanced Memory and Neural Computing
- CCD and CMOS Imaging Sensors
- Synthesis and properties of polymers
- Low-power high-performance VLSI design
- VLSI and FPGA Design Techniques
- Optical Coatings and Gratings
- Analog and Mixed-Signal Circuit Design
- Optical Network Technologies
- Advancements in Semiconductor Devices and Circuit Design
- Electronic Packaging and Soldering Technologies
- Neuroscience and Neural Engineering
- Advanced Photonic Communication Systems
- Microwave Engineering and Waveguides
- PAPR reduction in OFDM
Korea Advanced Institute of Science and Technology
2009-2024
Pohang University of Science and Technology
2015-2024
Yonsei University
2024
Korea Hydrographic and Oceanographic Agency
2024
Korea Institute of Industrial Technology
2019-2024
Samsung (South Korea)
2007-2023
Chung-Ang University
2020-2023
Virginia Tech
2023
Electronics and Telecommunications Research Institute
2011-2021
Seoul National University
2014-2020
We demonstrate a novel on-board chip-to-chip optical interconnect using long-range surface plasmon polariton (LR-SPP) waveguides that feature 2.5-cm-long gold strips embedded in low loss polymer cladding. A TM-mode vertical-cavity surface-emitting laser (VCSEL) operating at wavelength of 1.3 microm was butt-coupled into the order to excite fundamental LR-SPP mode and then transmitted light received with photo-diode (PD). The waveguide width is varied range 1.5-5.0 optimize insertion where...
We report on an insulating two-dimensional material, hexagonal boron nitride (h-BN), which can be used as effective wrapping layer for surface-enhanced Raman spectroscopy (SERS) substrates. This material exhibits outstanding characteristics such its crystallinity, impermeability, and thermal conductance. Improved SERS sensitivity is confirmed Au substrates wrapped with h-BN, the mechanism of investigated via h-BN thickness-dependent experiments combined theoretical simulations. The...
Based on the thermo-optic tuning of a polymer waveguide Bragg reflector, we demonstrated cost-effective tunable wavelength laser for WDM optical communications. The excellent effect enabled direct reflection by controlling electrical power micro-heater. Wavelength 32 channels with 0.8 nm spacing was as well continuous steps 0.1 nm. To be qualified WDM-PON applications, stability within 0.15 confirmed an operating temperature range from -10 to 70 degrees C.
A hybrid plasmonic waveguide structure is proposed and fabricated for low-loss lightwave guiding along a metal stripe core. By embedding Au in dual slab waveguides with high refractive-index contrast, the field of guided mode confined more two dielectric core layers. Thus, propagation loss significantly reduced. The like combination fundamental long-range surface plasmon polariton strip symmetric mode. We fabricate 5 nm-thick optical measure properties at wavelength 1.31 microm. less than...
This paper aims to present the design and achieved results on a CMOS electronic photonic integrated device for low cost, power, transparent, mass-manufacturable optical switching. An unprecedented number of components (more than 1000), each individually electronically controlled, allows realization transponder aggregator which interconnects up eight transponders four direction colorless-directionless-contentionless ROADM. Each supports 12 200-GHz spaced wavelengths, can be independently...
Nozzle clogging during continuous casting of Ti-ULC (Ultra Low C) steel was investigated by inspections plant-used SENs and laboratory scale experiments using a rotating finger method. Various Al/Ti ratios in the different kinds nozzles (with or without CaO) were employed. Clog deposits found used composed complicated oxide (CaO–Al2O3–TiOx-…), Fe drops chunks. Increasing Ti concentration increased amount deposit metallic deposits. In experiments, increasing effective to suppress formation...
In this article, for the first time, we propose a transformer network-based reinforcement learning (RL) method power distribution network (PDN) optimization of high bandwidth memory (HBM). The proposed can provide an optimal decoupling capacitor (decap) design to maximize reduction PDN self- and transfer impedance seen at multiple ports. An attention-based is implemented directly parameterize decap policy. optimality performance significantly improved since attention mechanism has powerful...
Split learning (SL) is an emergent distributed framework which can mitigate the computation and wireless communication overhead of federated learning. It splits a machine model into device-side server-side at cut layer. Devices only train their allocated transmit activations layer to server. However, SL lead data leakage as server reconstruct input using correlation between intermediate activations. Although allocating more layers reduce possibility leakage, this will energy consumption for...
In this paper, we present a design method for compact inverted Doherty power amplifier (IDPA), which has high-efficiency and high-power characteristics. An optimum load matching network an additional offset line, after the of carrier amplifier, dynamically modulate impedance according to input drive, while conventional uses quarter-wave line do it. The operational principles guide are provided. For experimental verification, 50-W was designed pi/4 differential quadrature phase-shift keying...
We demonstrate a high bit-rate optical signal transmission by using long-range surface plasmon polariton (LRSPP) waves in guided geometry. With 40Gbit∕s communication signal, eye patterns and bit-error-rates were measured to access the quality of properties LRSPP mode. A thin gold strip line embedded low loss polymer supports mode, which propagates with 2dB∕cm loss, couples standard single mode fibers at 1.55μm 2dB coupling loss. was transmitted via 4cm long waveguide without any distortion...
This paper presents a new reconfigurable carrier leakage canceler for UHF RFID readers, using directional coupler and an impedance tuning circuit to improve the sensitivity of receiver. The circuit, which consists electrically tunable passive components, can be adaptively tuned have optimum reflection coefficient cancellation. In order secure good cancellation performance over wide operating frequency band, PIN varactor diodes are used as variable resistor capacitor, respectively, circuit....
Hardware-based external monitors have been proposed as a trustworthy method for protecting the kernel integrity. We introduce design and implementation of Address Translation Redirection Attack (ATRA) that enables complete evasion hardware-based monitor anchors its trust on separate processor. ATRA circumvents by redirecting memory access to critical objects into non-monitored region. Despite seriousness issue, address translation integrity has assumed in many possibility exploitation...
A network-on-chip (NoC) is applied to achieve extensive communication bandwidth required for parallel computing. 125 GOPS NoC-based processor with a bio-inspired visual attention engine (VAE) exploits both data and object-level parallelism while dissipating 583 mW by packet-based power management. The use of more PEs, VAE, low latency NoC enables higher performance efficiency over the previous design. consisting 12 IPs: main processor, 8 PE clusters (PECs), matching accelerator (MA), an...
Tissue scattering and absorption impact the excitation emission light in different ways for multiphoton imaging. The collected fluorescence includes both ballistic photons scattered whereas excited signal within focal volume is mostly generated by photons. of wavelengths on imaging has been extensively investigated before; however, experimental data lacking to evaluate attenuation deep Here we perform three-photon mouse brain vasculature vivo using green, red, near-infrared fluorophores,...
To improve the propagation loss of polymer-based long-range surface-plasmon-polariton (LR-SPP) waveguide devices at telecom wavelength range, low-loss LR-SPP waveguides were fabricated in an ultraviolet-curable acrylate polymer with a low refractive index and absorption loss. A 1.72 dB/cm 1.55 mum was achieved 14-nm-thick 3-mum-wide metal stripe.
This paper presents a linearized two-stage amplifier integrated circuit (IC), having an output power level of about 1 Watt, used for general purpose applications. A predistortion method, based on alignment the nonlinear characteristics between first- and second-stage amplifiers, has been proposed analyzed in order to enhance linearization aspects. The resistors active bias circuits both stages are optimized achieve best cancellation conditions third-order intermodulation components. IC,...
We report the first measurement of optical constants evaporated gold films by using surface plasmon resonance curve fitting method with an attenuated total reflection device from 16 to 70 nm thickness at telecommunication wavelengths. The results that were obtained are in good agreement those ellipsometry. Until now, thin metal known change according due variation electrical resistivity. This phenomenon is also verified this study a simple measurement. It observed for thicknesses less than...
We present characteristics of very thin Au strip waveguides based on long-range surface plasmon polaritons (LR-SPPs) along strips embedded in polymers. also report a 10 Gbps optical signal transmission via LR-SPPs with the pig-tailed waveguide at telecommunication wavelength 1.55 mum. limited thickness, width, and length up to ~20 nm, ~ mum, ~5 cm, respectively, for practical applications. At loss properties were theoretically experimentally evaluated width cladding material. The lowest...
This paper presents the Visual Attention Engine (VAE), which is a digital cellular neural network (CNN) that executes VA algorithm to speed up object-recognition. The proposed time-multiplexed processing element (TMPE) CNN topology achieves high performance and small area by integrating 4800 (80 × 60) cells 120 PEs. Pipelined operation of PEs single-cycle global shift capability result in PE utilization ratio 93%. are implemented 6T static random access memory-based register files dynamic...
We demonstrate sub-dB/cm propagation losses in polymer-based silver stripe waveguides at the wavelength of 1.31 microm. The were fabricated a low-loss fluorinated polymer clad. To form uniform metal patterns, which are essential for reducing loss, we developed lift-off process using double layers photoresist and SiNx. A loss less than 1.0 dB/cm was obtained with 11- nm-thick stripes width range 1.5 - 4.5 coupling approximately dB polarization maintaining single mode fiber achieved For 2.0...
A 228GOPS 345 mW heterogeneous many-core processor combines bottom-up and top-down attention for high accuracy. It uses analog-digital mixed-mode neuro-fuzzy inference circuits to realize robust object recognition. Weight perturbation learning workload-aware voltage/frequency control are adopted. The 5 × 10 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> chip with 96% recognition accuracy contains 4 SIMD vector processing elements 32...
This brief presents an ultrabroadband (2- to 600-MHz band) linear power amplifier using a compact frequency-selective analog predistorter, which includes capacitor having optimized capacitance and biased Schottky diode connected in series. It is shunted at the input of main has third-order intermodulation generation capability its capacitance. A two-stage push-pull amplifier, operation range from 2 600 MHz, was implemented linearized proposed predistorter. exhibited high 1-dB compression...