• 한국광학회:학술대회논문집
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• 한국광학회 1989년도 제4회 파동 및 레이저 학술발표회 4th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.218-221
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• 1989

Buried Bragg reflectors which are immune to the contamination of the surface of an optical waveguide chip are fabricated on Si3N4-SiO2 rib optical waveguides on Si. The effective refractive indices and the bandwidths of the fabricated buried Bragg reflector waveguides are determined by transmission measurement. We show that the measured values of the effective refractive indices are consistent with the calculated values as the width of the waveguide rib varies. Propagation losses of the guided modes due to the leakage into the si substrate are also calculated.

• 한국통신학회논문지
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• 제21권12호
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• pp.3277-3285
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• 1996

In this paper, w designed an opical power distribution device for application to an optical switching and an optical subscriber loop. We fabricated PSG thin film by LPCVD. Based on the measured index of fabricted thin film, rib-type waveguide was transformed to two-dimension by the effective index method and we simulated dispersion property to find asingle-mode condition. We found that the optimum design parameters of rib-type waveguide are:cladding layer of 3.mu.m, core layer of 3.mu.m, buffer layer of 10.mu.m, and core width of 4.mu.m. Each side of the guiding region was etched down to 4.mu.m to shape the core. We used these optimum parameters of the rib-type waveguide with branching angle of 0.5.deg. and simulted the Y-branch waveguide by the BPM simulation. Numerical loss in branching area was claculated to be 0.1581dB and equal to the total loss of the Y-branch. The loss of the fabricated Y-branch waveguide on PSG film ws 1.6dB at .lambda.=1.3.mu.m before annealing but was 1.2dB after annealing at 1000.deg. C for 10 minutes. Consequently, the loss of branching area from 3000.mu.m to 6000.mu.m in the z-direction was 0.8dB, and single-mode propagation was confirmed by measuring the near field pattern. For coupling the fabricated Y-branch waveguide with an optical fiber, we fabricated V-groove which was used as the upholder of optical fiber. An etching angle was 54.deg. and the width and depth of guiding groove was 150.mu.m, 70.mu.m, respectively. The optical fiber is inserted onto V-groove. Both the Y-branch and V-groove were connected through the index matching oil. Coupling loss after connecting Y-branch and the optical fiber on V-groove was 0.34dB and that after injecting index mateching oil was 0.14dB.

• Current Optics and Photonics
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• 제4권1호
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• pp.81-81
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• 2020

• 센서학회지
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• 제29권3호
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• pp.172-179
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• 2020

We studied an integrated-optic biosensor configuration that operates at a wavelength of 0.63 ㎛ based on the evanescent-wave and two horizontal mode power coupling of Si₃N₄ rib-optical waveguides formed on a Si/SiO₂/Si₃N₄/SiO₂ multilayer thin films. The sensor consists of a single-mode input waveguide, followed by a two-mode section which acts as the sensing region, and a Y-branch output for separating the two output waveguides. The coupling between the two propagating modes in the sensing region produces a periodically repeated optical power exchanges along the propagation. A light power was steered from one output channel to the other due to the change in the cladding layer (bio-material) refractive index, which affected the effective refractive index (phase-shift) of two modes through evanescent-wave. Waveguide analyses based on the rib optical waveguide dimensions were performed using various numerical computational software. Sensitivity values of 12~23 and 65~165 au/RIU, respectively for the width and length of 4 ㎛, and 3841.46 and 26250 ㎛ of the two-mode region corresponding to the refractive index range 1.36~1.43 and 1.398~1.41, respectively, were obtained.

• 한국광학회지
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• 제30권1호
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• pp.15-22
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• 2019

소산파 기반 집적광학 바이오센서에 적합한 $Si_3N_4$ 립-광도파로 구조에 대한 해석적 분석을 통해서 단일모드 도파조건을 도출하였다. 두-모드 간섭현상을 이용하는 집적광학 바이오센서 구조를 제시하고, 단일모드와 두-모드(감지영역)에 해당되는 립-광도파로 제원인 폭, 립 및 코어 두께 각각에 대해서 $3{\mu}m$, 2 nm, 150 nm와 $3{\mu}m$, 20 nm, 340 nm를 제안하였으며, FMM 전산해석을 통해서 감지영역의 두-모드들에 대한 광학적 특성들을 검토하였다.

• 전기전자학회논문지
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• 제24권2호
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• pp.409-418
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• 2020

본 논문에서는 Si/SiO₂/Si₃N₄/SiO₂ 적층 구조를 갖는 Si₃N₄ 립-광도파로 기반의 다중모드 간섭기를 활용하는 집적광학 소산파 바이오센서에 대해서 서술하였다. 다중모드 간섭기의 이론적 배경에 대해서 검토하였고, 전산해석을 통해서 다중모드 간섭기 구조와 설계과정을 제시하였다. 다중모드 간섭기의 제원 (길이, 폭)이 소자 성능에 어떻게 영향을 미치는지 분석하였다. 분석물질의 굴절률 변화가 다중모드 간섭기의 모드 패턴형성 위치와 출력 광파워에 많은 영향을 미치고 있음을 확인하였고, 이 특성을 적용할 경우 집적광학 바이오센서로 활용 가능함을 입증하였다.

• 전자공학회논문지A
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• 제32A권8호
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• pp.153-165
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• 1995

The design procedure of a GaAs/AlGaAs semiconductor matrix optical switch is presented for a simplified tree architecture in the viewpoint of optical loss. A low loss, 0.537 dB/cm, pin type substrate is designed by considering the loss due to imputity doping at 1.3 $\mu$m wavelength. The operating voltage and the device length of a reversed ${\Delta}{\beta}$ electro-optic directional coupler(EODC) swith which is a cross-point device of the 4${\times}$4 matrix optical switch and the bending loss of rib waveguide are caculated as functions of waveguide parameters and bending parameters. There is an optimum bending radius for some waveguide parameters. It is recommened that higher optical confinement conditions such as wide waveguide width and higher rib-height should be chosen for structural parameters of a low loss and a process insensitive 4${\times}$4 matris optical switch. A 4${\times}$4 optical matrix switch which has a 3 dB loss and a 12 volt operating voltage is designed.

• 전자공학회논문지D
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• 제34D권4호
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• pp.79-86
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• 1997

An electro-optic polymer digital optical switch with rib waveguides is designed and fabricated by using the RIE method. POlarization-independent and wavelength-insensitive operation is demonstrated at the wavelengths of 1.3mm and 1.55mm, for the first time in electro-optic polymer-based devices. The rib waveguides have been designed to achieve good guiding properites for both TE and TM polarizations by controlling the etching depth as well as its aspect ratio. Especially theetching depth is controlled to change the guided mode profiles of the rib waveguide and thus to achieve an optimum coupling in the branch. The measured crosstalk is better than -16dB and the extincton ratio of each output port is greater than 16dB.

• 한국광학회지
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• 제11권2호
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• pp.119-122
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• 2000

본 논문에서는 폴리머 립 광도파로에 적합한 모드 모양 변환기를 제안했다. 제안된 모드 모양 변환기는 이중 립 구조를 갖고 광섬유의 큰 원형 단일모드를 일반적인 립 광도파로의 작은 타원형 단일모드로 변화 시켰다. 또한 제안된 모드 모양 변환기는 폴리머 매질을 기반으로 하는 광도파로 소자 제작 공정에 매우 적합하다. 3차원 BPM을 통해 모드 볼일치에 의한 결합 손실이 0.079 dB/facet이고 모드 모양 변환기에 의한 전체 손실이 0.2 dB 미만임을 보였다.

• 대한전자공학회논문지
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• 제23권6호
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• pp.833-839
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• 1986

This paper describes the development of a new type of an integrated optical filter using the frequency characteristics of a directly-connected directional coupler with a Rib waveguide. It has been designed for multiplexing and demultiplexing light froups in different wavelength regions. Also, the effects of higher modes, couplings between input waveguides or output waveguides, and dispersion of material are considered.