• Current Optics and Photonics
• /
• v.6 no.1
• /
• pp.10-14
• /
• 2022

Low-threshold optical bistability is essential for practical nonlinear optical applications. Many bistable optical devices based on high-quality-factor resonators have been proposed to reduce the threshold intensity. However, demonstrating high-quality-factor resonance requires complex fabrication techniques. In this work, we numerically demonstrate optical bistability with bound states in the continuum in a simple one-dimensional Si photonic crystal. The designed structure supports bound states in the continuum, producing an ultrahigh quality factor without tough fabrication conditions. The threshold intensity of the designed device is 150 MW/cm² at the optical communication wavelength. This scheme may lead to a new class of nonlinear photonics.

• Journal of the Optical Society of Korea
• /
• v.16 no.4
• /
• pp.432-442
• /
• 2012

In this paper, we propose, analyze and simulate the performances of some new plasmonic logic gates in two dimensional plasmonic waveguides with nanodisk resonators, using the numerical method of finite difference time domain (FDTD). These gates, including XOR, XNOR, NAND, and NOT, can provide the highly integrated optical logic circuits. Also, by cascading and combining these basic logic gates, any logic operation can be realized. These devices can be utilized significantly in optical processing and telecommunication devices.

• Korean Journal of Optics and Photonics
• /
• v.1 no.2
• /
• pp.223-239
• /
• 1990

This paper presents an overview on the present status and future trends of photonic physics and engineering as applicable to optical materials and devices that would enable optical information processing and optical commmication technologies of the future. Covered subjects include semiconductor quantum devices, organic materials, photorefractive physics, quantum effect, non-linear processing optical amplification, memory, integrated optics, and applications in all-optical communications and processing, including photonic switching.

• Proceedings of the Optical Society of Korea Conference
• /
• 2005.02a
• /
• pp.292-295
• /
• 2005

Variable optical attenuators (VOA) made of low-loss fluorinated polymers are demonstrated which shows a low operating power less than 30 mW due to the superior thermo-optic effect of polymer material and a low insertion loss less than 1.0 dB by incorporating highly fluorinated polymers to reduce the absorption loss at 1550 nm. An attenuator-integrated low-crosstalk polymeric digital optical switch (DOS) is also demonstrated. The switch and attenuator shares a single connected electrode which is controlled by a single current source. Due to the simple structure of the integrated attenuator, the device length is reduced to 1 cm so as to provide low insertion loss of 0.8 and 1.1 dB for 1300 and 1550 nm, respectively. The attenuator radiates remained optical signal on the switch-off branch in order to decrease the switching crosstalk to be less than -70 dB with an applied electrical power of 200 mW.

• ETRI Journal
• /
• v.28 no.1
• /
• pp.103-106
• /
• 2006

We have fabricated a planar lightwave circuit (PLC) hybrid-integrated optical sub-assembly of a triplexer using a thin film filter (TFF)-attached wavelength division multiplexer (WDM) and photodiode (PD) carriers. Two types of TFFs were attached to a diced side of a silica-terraced PLC platform, and the PD carriers with a $45^{\circ}$ mirror on which pin-PDs were bonded were assembled with the platform. A clear transmitter eye-pattern and minimum receiver sensitivity of -24.5 dBm were obtained under 1.25 Gb/s operation for digital applications, and a second-order inter-modulation distortion (IMD2) of -70 dBc was achieved for an analog receiver.

• ETRI Journal
• /
• v.34 no.3
• /
• pp.361-368
• /
• 2012

A complete high-frequency small-signal circuit model of a 40 Gb/s butterfly electroabsorption modulator integrated laser module is presented for the first time to analyze and optimize its electro-optic (E/O) response and reflection characteristics. An agreement between measured and simulated results demonstrates the accuracy and validity of the procedures. By optimizing the bonding wire length and the impedance of the coplanar waveguide transmission lines, the E/O response increases approximately 5% to 15% from 20 GHz to 33 GHz, while the signal injection efficiency increases from approximately 15% to 25% over 18 GHz to 35 GHz.

• Korean Journal of Optics and Photonics
• /
• v.4 no.3
• /
• pp.294-300
• /
• 1993

Monolithic NOR and INVERTER active optical logic devices inte- grated with surface-emitting microlasers, heterojunction photo- transistors(HPT) in parallel and resistors in series are characterized. The differential quantum efficiency of the typical AlGaAs superlattice microlaser integrated in the active optical logic devices is 15%. Current gain of the HPT is 57, when emitter-collector voltage and input optical power are 4 V and $50{\mu}W$, respectively. $57{\mu}W$ of output power from the active optical logic device decreases to zero when $47{\mu}W$ of input optical power is incident on the HPT part of the active logic device.

• Journal of the Semiconductor & Display Technology
• /
• v.14 no.4
• /
• pp.67-71
• /
• 2015

Product of technology developed in this study is an external interface for controlling the equipment of pendant key remote control system circuit board, and it is used in the electronic component test equipment system. Main control system module is in the role as a device for controlling the various control devices that make up the integrated system for microscopic examination at the request of the host computer engineers to control the inspection equipment. The pentane-key interface module to its role as a device for controlling the various control devices that make up the integrated system for microscopic examination at the request of the host computer for the engineer to control the inspection equipment. Development of the control system can be expected in the configuration of a system for efficient and accurate inspection of high-precision parts.

• Journal of Institute of Control, Robotics and Systems
• /
• v.6 no.8
• /
• pp.666-671
• /
• 2000

With the current advances in optical WDM (Wavelength Division Multiplexing) networking technologies and the increasing demand for network bandwidth the Next Generation Internet is expected to be a network that runs IP(Internet Protocol) directly over WDM-based optical networks. The network control architecture for the IP over WDM networks is different from that of traditional Internet since the underlying WDM devices have more constraints than electronic IP routers such as the lack of optical buffers and wavelength continuity property etc. In this paper we introduce several architectural models for implementing IP over WDM networks and propose an integrated network control framework for the IP over WDM networks. This framework leverages the traffic engineering control architecture for the MPLS (Multi-Protocol Label Switching) networks and is mainly developed for the IP over packet-switched WDM networks. We also report several preliminary simulation results of contention resolution schemes in the packet-switched WDM networks.

• Proceedings of the Optical Society of Korea Conference
• /
• 2006.07a
• /
• pp.209-210
• /
• 2006