• Title/Summary/Keyword: 광집적소자

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A study on the enhancement of refractive index in Ti:LiTaO$_{3}$ optical waveguides by Zn-vapor diffusion (Zn-Vapor확산에 의한 Ti:LiTaO$_{3}$ 광도파로의 굴절률 증가에 관한 연구)

  • 정홍식;정영식
    • Electrical & Electronic Materials
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    • v.9 no.3
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    • pp.298-303
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    • 1996
  • A double diffusion technique is developed to enhance the effective mode index of optical waveguides in $LiTaO_3$. It consists of Zn diffusion from the vapor phase at relatively low temperatures (750->$800^{\circ}C$), into waveguides initially produced by Ti indiffusion at higher temperature (1150->$1200^{\circ}C$). Both X- and Z-cut substrates are investigated. A model that combines profiles of both diffusion is formulated to calculate the expected effective index values for planar waveguides. Good agreement is found between experimental results and model predictions which assume that the initial Ti profile is not affected by the lower temperature Zn diffusion. Effective index enhancements as high as 0.005 and 0.003 are obtained by this method for the fundamental extraordinary and ordinary modes, respectively.

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A Study on Electrooptic $Ti:LiNbO_3$ Mach-Zehnder integrated-optic interferometers for Electric-Field Measurement (전계측정용 전기광학 $Ti:LiNbO_3$ Mach-Zehnder 집적광학 간섭기에 관한 연구)

  • Jung, Hong-Sik
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.12
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    • pp.15-22
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    • 2011
  • Integrated-optic symmetric/asymmetric Mach-Zehnder interferometers at $1.3{\mu}m$ wavelength were studied as sensing part for electric-field measurement system. The devices were simulated based on the BPM software and fabricated utilizing Ti-diffused $LiNbO_3$ channel optical waveguides and lumped-type electrodes. A half-wave voltage of $V_{\pi}$=6.6V and modulation depth of 100% and 75% for a symmetric structure were measured for 200Hz and 1kHz electrical signal bandwidth, respectively. By the way, almost half-maximum power transmission was observed for asymmetric interferometers with ${\pi}$/2 intrinsic phase difference. Expected experimental measurements were observed for 1kHz electrical signal bandwidth.

A Study on the Fabrication of Integrated Optical Electric-Field Sensor and Performance utilizing Asymmetric $Ti:LiNbO_3$ Mach-Zehnder Interferometer (비대칭 $Ti:LiNbO_3$ Mach-Zehnder 간섭기를 이용한 집적광학 전계센서 제작 및 성능에 관한 연구)

  • Ha, Jeongho;Jung, Hongsik
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.10
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    • pp.128-134
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    • 2012
  • The performance evaluation and fabrication of integrated-optic electric-field sensor utilizing $Ti:LiNbO_3$ asymmetric Mach-Zehnder intensity modulator with a push-pull lumped electrode and a plate-type probe antenna to measure an electric field strength is described. The modulator has a small device size of $46{\times}7{\times}1\;mm$ and operates at a wavelength $1.3{\mu}m$. The devices are simulated based on the BPM software and fabricated utilizing Ti-diffused $LiNbO_3$ channel optical waveguides. The minimum detectable electric field is 1.02 V/m and 6.91 V/m, corresponding to a dynamic range of ~35 dB and ~10 dB at the frequencies of 500 KHz and 5 MHz, respectively.

A Study on the Integrated-Optical Electric-Field Sensor utilizing Ti:LiNbO3 Y-fed Balanced-Bridge Mach-Zehnder Interferometric Modulators (Ti:LiNbO3 Y-fed Balanced-Bridge 마하젠더 간섭 광변조기를 이용한 집적광학 전계센서에 관한 연구)

  • Jung, Hongsik
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.1
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    • pp.29-35
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    • 2016
  • We have demonstrated a $Ti:LiNbO_3$ electro-optic electric-field sensors utilizing a $1{\times}2$ Y-fed balanced-bridge Mach-Zehnder interferometric (YBB-MZI) modulator which uses a 3-dB directional coupler at the output and dipole patch antenna. The operation and design were proved by the BPM simulation. A dc switching voltage of ~16.6 V and an extinction ratio of ~14.7 dB are observed at a wavelength of $1.3{\mu}m$. For a 20 dBm rf power, the minimum detectable electric-fields are ~1.12 V/m and ~3.3 V/m corresponding to a dynamic range of about ~22 dB and ~18 dB at frequencies 10 MHz and 50 MHz, respectively. The sensors exhibit almost linear response for the applied electric-field intensity from 0.29 V/m to 29.8 V/m.

Technical Trends of Photonic Integrated Circuits for High Speed, High Capacity Optical Communication (초고속 대용량 광통신을 위한 광집적 소자 기술 동향)

  • Baek, Y.S.
    • Electronics and Telecommunications Trends
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    • v.24 no.6
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    • pp.52-60
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    • 2009
  • 인터넷의 보급과 더불어 폭발적으로 늘어나기 시작한 데이터 통신은 FTTH의 보급과 IPTV, VoD 등 본격적인 멀티미디어 수요의 증가에 따라 매 18개월마다 통신량이 2배씩 증가하는 "광 무어의 법칙"이 성립되고 있다. 지속적인 대역폭의 증가를 수용하기 위해서는 핵심 광부품의 소형화 및 저가화가 반드시 필요하며 이러한 요구사항 수용을 위한 핵심요소는 광집적화 기술 개발을 통한 광소자의 고집적화 및 고속화 달성이다. 광집적화 기술은 크게 두 가지 분류로 나눌 수 있는데 이종 물질간의 하이브리드결합에 의한 구현과 단일 혹은 유사 물질에 의한 모놀리식 집적에 의한 방법이다. 본 고에서는 하이브리드 집적 및 모놀리식 집적 기술의 핵심 요소 및 기술발전 현황에 대해 살펴본다.

Optimization of Optical Coupling Properties of Active-Passive Butt Joint Structure in InP-Based Ridge Waveguide (InP계 리지 도파로 구조에서 활성층-수동층 버트 조인트의 광결합 효율 최적화 연구)

  • Song, Yeon Su;Myeong, Gi-Hwan;Kim, In;Yu, Joon Sang;Ryu, Sang-Wan
    • Journal of the Microelectronics and Packaging Society
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    • v.27 no.4
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    • pp.47-54
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    • 2020
  • Integration of active and passive waveguides is an essential component of the photonic integrated circuit and its elements. Butt joint is one of the important technologies to accomplish it with significant advantages. However, it suffers from high optical loss at the butt joint junction and need of accurate process control to align both waveguides. In this study, we used beam propagation method to simulate an integrated device composed of a laser diode and spot size converter (SSC). Two SSCs with different mode properties were combined with laser waveguide and optical coupling efficiency was simulated. The SSC with larger near field mode showed lower coupling efficiency, however its far field pattern was narrower and more symmetric. Tapered passive waveguide was utilized for enhancing the coupling efficiency and tolerance of waveguide offset at the butt joint without degrading the far field pattern. With this technique, high optical coupling efficiency of 89.6% with narrow far field divergence angle of 16°×16° was obtained.

Optical Characteristics of Two-dimensional Silicon Photonic Crystal Slab Structures with Air and Silica Cladding (공기 및 실리카 클래딩을 갖는 2차원 실리콘 광자 결정 슬랩 구조의 광학적 특성)

  • Lee, Yoon-Sik;Han, Jin-Kyu;Song, Bong-Shik
    • Korean Journal of Optics and Photonics
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    • v.20 no.4
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    • pp.211-216
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    • 2009
  • Much research into two-dimensional (2-D) photonic crystal (PC) structures has been conducted for realization of ultrasmall optical integrated circuits. A 2-D silicon (Si) PC slab structure with air cladding (n=1) is one of the representative structures in 2-D PCs. While air-clad Si PC slab structures have good optical characteristics, their suspension in air can lead to mechanical weakness, making integration with some optical devices difficult. In this paper, we propose improving the mechanical robustness of PC structure by developing a 2-D Si PC structure with symmetric silica cladding (n=1.44) and comparing its optical properties to that of the air-clad structure. First, we investigate the optical properties of a 2-D Si PC slab structure with air cladding by using a 3-D finite difference time domain method. We determined that a photonic bandgap of 330 nm and a non-leaky propagating bandwidth of 100 nm in the optical communication range are possible. Next, we investigate the optical properties of 2-D Si PC slab structures with silica cladding. Even though the refractive index of the silica cladding is higher than that of air, we developed a silica-clad structure with good optical properties: a photonic band gap of approximately 230 nm and a non-leaky propagating bandwidth of 90 nm, comparable to that of the air-clad PC structures.