• International Journal of Aeronautical and Space Sciences
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• 제3권2호
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• pp.24-30
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• 2002

This paper demonstrates a comparison of linear and nonlinear analyses for thermo-optic effects of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include theoretical analyses and experiment of the etched planar waveguide Bragg grating optical temperature sensor. Theoretical models with nonlinear than linear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance.

• 한국정보통신학회논문지
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• 제10권11호
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• pp.2049-2054
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• 2006

본 연구는 에칭된 실리카 기반의 평면 도파로 Bragg grating에 기반한 광 온도센서의 열전 광 효과에 대한 선형 및 비선형 해석에 대하여 제시하였다. 또한, 에칭된 평면 도파로 Bragg grating 광 온도센서의 이론적인 해석과 실험을 행하고 그 결과를 나타내었다. 도파로에 기반한 grating응답에 대하여 선형 온도 효과보다 비선형의 이론적 모델과 plate deformation이론이 허용오차 범위 내에서의 실험치와 일치함을 알 수 있었다.

• 한국전기전자재료학회논문지
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• 제11권6호
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• pp.472-476
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• 1998

The surface reactions of silica film($SiO_2-P_2O_5-B_2O_3-GeO_2$) with fluorocarbon plasma has been studied by using angle -resolved x-ray photoelectron spectroscopy(XPS). It has been confirmed that residual carbon consists of C-C and C-CFx bonds and fluorine mainly binds silicon in the case of etched silica by using $CF_4$ gas plasma. The surface reaction of silica with various fluorocarbon gases, such as $CF_4,C_2F_6 and CHF_3$ were investigated. XPS results showed that though the etching gases were changed, the elements and binding states of the residual layers on the etched silica by using various fluorocarbon gas plasma were nearly the same . This seems to be due to the high volatility of byproducts, that is, $SiF_4 and CO_2$ etc..

• 한국광학회:학술대회논문집
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• 한국광학회 2004년도 제15회 정기총회 및 동계학술발표회
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• pp.318-319
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• 2004

• 한국레이저가공학회지
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• 제18권1호
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• pp.7-11
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• 2015

In this paper, micro trench structure is fabricated by femtosecond laser for inserting optical reflecting wavelength filter in planar waveguide. The width and depth of the trench is controlled by femtosecond laser machining condition. Also, large scale of single channel with 500um and 1000um on silica plate is fabricated by femtosecond laser, and roughness of the channel surface is polished by $CO_2$ laser for the insertion of the filter. Then, the characteristic of the planar waveguide inserted the filter is verified.

• 한국세라믹학회지
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• 제39권6호
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• pp.594-597
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• 2002

플라즈마 화학기상증착(PECVD)법을 이용하여 p-type Si(100) 웨이퍼에 Silicon Oxynitride(SiON) 후막을 SiH$_4$ , $N_2$O, $N_2$ 가스를 혼합하여 증착하였다. Prism coupler측정을 통해 SiON 후막의 굴절률 1.4620~1.5312을 얻었으며, rf power가 180 W에서 5.92$\mu$m/h의 증착률을 나타내었다. 증착변수에 따른 화학적 조성의 영향은 X-ray Photoelectron Spectroscopy(XPS) 을 통하여 관찰하였다. 또한, SiON 후막 증착후에 $1.5\mu$m 부근의 흡수띠를 제거하기 위해 105$0^{\circ}C$의 $N_2$ 분위기에서 2시간 동안 열처리를 행하였다.

• ETRI Journal
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• 제38권5호
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• pp.981-987
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• 2016

We present a cost-effective dual polarization quadrature phase-shift coherent receiver module using a silica planar lightwave circuit (PLC) hybrid assembly. Two polarization beam splitters and two $90^{\circ}$ optical hybrids are monolithically integrated in one silica PLC chip with an index contrast of $2%-{\Delta}$. Two four-channel spot-size converter integrated waveguide-photodetector (PD) arrays are bonded on PD carriers for transverse-electric/transverse-magnetic polarization, and butt-coupled to a polished facet of the PLC using a simple chip-to-chip bonding method. Instead of a ceramic sub-mount, a low-cost printed circuit board is applied in the module. A stepped CuW block is used to dissipate the heat generated from trans-impedance amplifiers and to vertically align RF transmission lines. The fabricated coherent receiver shows a 3-dB bandwidth of 26 GHz and a common mode rejection ratio of 16 dB at 22 GHz for a local oscillator optical input. A bit error rate of $8.3{\times}10^{-11}$ is achieved at a 112-Gbps back-to-back transmission with off-line digital signal processing.

• ETRI Journal
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• 제34권6호
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• pp.946-949
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• 2012

We present the optimization of a birefringence-enhanced-waveguide (BWG)-based polarization beam splitter (PBS) in a Mach-Zehnder interferometer (MZI) configuration and analyze the structure-dependent or polarization-dependent phase difference, using a delay-line MZI (DL-MZI). We fabricate the DL-MZI using silica-based planar lightwave circuit technology and, using the DL-MZI, demonstrate the ability to optimize a PBS by measuring the birefringence of the BWG and structure-dependent phase offset.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.141-144
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• 2002

Computer code was developed to design waveguide gratings based on coupled-mode equations and the transfer matrix formalism. The experimental set-up has been constructed for inscribing Bragg gratings in planar waveguides with a phase mask and uv laser beam, which enables alignment and packaging of grating devices as well as in-situ performance measurements. Bragg grating has been fabricated on silica planar waveguides with 0.75% Germanium concentration and its transmittance spectrum was measured to have 95% reflectance at the peak wavelength. Optical losses as the function of the misalignment were measured and their usage is described.

• ETRI Journal
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• 제27권4호
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• pp.446-448
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• 2005

Using tightly focused femtosecond laser pulses, we produce an optical waveguide and devices in transparent materials. This technique has the potential to generate not only channel waveguides, but also three-dimensional optical devices. In this paper, an optical splitter and U-grooves, which are used for fiber alignment, are simultaneously fabricated in a fused silica glass using near-IR femtosecond laser pulses. The fiber- aligned optical splitter has a low insertion loss, less than 4 dB, including an intrinsic splitting loss of 3 dB and excess loss due to the passive alignment of a single-mode fiber. Finally, we present an output field pattern, demonstrating that the splitting ratio of the optical splitter becomes approximately 1:1.