김태환 교수

With the growing demand for automotive LiDAR and the maturation of silicon photonics platforms, optical phased arrays (OPAs) have emerged as a key technology for solid-state optical beam-steering. In order to meet realistic automotive specifications with OPAs, >500 antenna elements should work reliably under tight power and cost budgets. Existing multi-chip solutions necessitate expensive packaging and assembly to achieve high interconnect density. Even with 2-D monolithic integration, high-volt

This work presents a hybrid-integrated 4- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula> micro-ring modulator-based wavelength-division multiplexed (WDM) optical transmitter (OTX) in the O-band, suitable for co-packaged optics. It supports up to 112 Gb/s per wavelength using high-bandwidth micro-ring modulators (MRMs) together with nonlinear equalization in the driver el

Recent years have witnessed the development of single-molecule localization microscopy as a generic tool for sampling diverse biologically relevant information at the super-resolution level. While current approaches often rely on the target-specific alteration of the point spread function to encode the multidimensional contents of single fluorophores, the details of the point spread function in an unmodified microscope already contain rich information. Here we introduce a data-driven approach in

We review the design trade-offs that exist in CMOS inverter-based shunt-feedback transimpedance amplifier (SF-TIA) when optimizing for energy efficiency. We analyze the performance of series and shunt inductive peaking techniques for bandwidth enhancement and identify the most effective one for low-power CMOS TIAs. As a design example, we present a 128-Gb/s single-ended linear transimpedance amplifier (TIA) intended for use in receivers for 400-G Ethernet optical modules and co-packaged optics.

Ga-doped n-type ZnO (ZnO:Ga) films were grown on sapphire substrates by rf magnetron sputtering and their structural, electrical and optical properties were characterized in detail. It was observed that high quality single crystal ZnO:Ga films are obtained, containing up to 1 wt% of Ga. The ZnO:Ga (1 wt%) films grown at 700 °C in pure O2 showed sharp and intense photoluminescence (PL) and high resolution x-ray diffraction (XRD) peaks, with full-width-at-half-maximum values of 150 meV (room tempe

Spin-orbit-torque (SOT) devices are promising candidates for the future magnetic memory landscape, as they promise high endurance, low read disturbance, and low read error, in comparison with spin-transfer torque devices. However, SOT memories are area intensive due to the requirement for two access transistors per bit. Here, we report a multibit SOT cell that has a single write channel shared among multiple bits, which enables an area-efficient memory design by reducing the number of access tra

We demonstrate a dual-polarization, single-wavelength transceiver with BER below soft-decision FEC (&lt;2.0e-2) at 320Gb/s (PAM-4) aggregate rate. The silicon photonic chip includes integrated laser, ring modulators, Si/Ge detectors, and polarization demux with automatic polarization control.

While current single-molecule localization microscopy (SMLM) methods often rely on the target-specific alteration of the point spread function (PSF) to encode the multidimensional contents of single fluorophores, we argue that the details of the PSF in an unmodified microscope already contain rich, multidimensional information. We introduce a data-driven approach in which artificial neural networks (ANNs) are trained to make a direct link between an experimental PSF image and its underlying para

In this paper, an effective feature which is capable of classifying targets among the detections obtained from 2D range-bearing maps generated in active sonar environments is proposed. Most conventional approaches for target classification with the 2D maps have considered magnitude of peak and statistical features of the area surrounding the peak. To improve the classification performance, HOG(Histogram of Gradient) feature, which is popular for their robustness in the image textures analysis is

NiO 산화물 타겟을 이용한 RF 마그네트론 스퍼터 방법으로 유리 기판 위에 NiO 박막을 Ar 가스만을 사용하여 증착하였으며, 증착 온도에 따라 NiO 박막 특성에 미치는 영향을 조사하였다. XRD 측정으로부터 증착된 박막의 결정구조는 <TEX>$200^{\circ}C$</TEX> 이하에서 (111) 면의 우선 배향성으로 보이다가 <TEX>$350^{\circ}C$</TEX> 이상에서 (220) 면의 우선 배향성을 가지는 다결정 입방구조임을 확인하였다. NiO 박막의 전기적 특성의 변화는 기판의 온도가 <TEX>$200^{\circ}C$</TEX>까지는 <TEX>$10^5\;{\Omega}cm$</TEX>의 부도체에 가까운 높은 비저항을 보였고 기판의 온도가 <TEX>$300^{\circ}C$</TEX> 이상에서는 <TEX>$10^{-1}{\sim}10^{-2}{\Omega}cm$</TEX>의 도체의 특성을 보이는 낮은 비저항으로 감소하는 Mott-Insulator Transiti

An all-digital nonlinear transmit-side equalization technique based on Model Predictive Control (MPC) is presented. The MPC equalizer performs an online optimization subject to eye height constraints at the RX using transmit waveform as a variable. Compared to existing TX equalization schemes such as IIR or Tomlinson-Harashima Precoding, MPC has been shown to achieve the best eye performance for any type of channel, especially when the control signal resolution is low, with minimal overhead at t

This paper presents the implementation of a high-throughput successive-cancellation decoder for a 1024-bit polar code. The proposed decoder processes the kernels in two successive layers in a fused manner within a cycle, so as to reduce the cycle count taken to decode a codeword. In addition, the log-likelihood ratios are represented in a redundant form to realize a high-speed kernel processing. As a result, the cycle period is not lengthened even with the fused kernel processing and thus achiev

The extra session of the 17th National Assembly convened lastly had passed the law on the promotion of the fire industry. Therefore, the development of the fire industry discussed insignificantly in accordance with the establishment of the law. In this important time, this study was intended to derive tasks for development through researching the concept and developing process of the fire industry and forecasting the industry. For defining the concept of the fire industry, this study researched