• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.160-163
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• 2002

Silica waveguide for an integrated diffractive optical head system was designed and fabricated. The waveguide was designed to optimize the optical efficiency of red and/or blue laser source, and a lab-made RF magnetron sputter was adopted to deposit silica cladding and core layers on SiO$_2$/Si substrates. The cladding and core layers were formed using commercial targets, and the former was done with ＃7740 and the latter with BK7 and BAK4, respectively The surface roughness of the waveguide layers was measured to be 30.3${\AA}$ for BK7 and 17.8${\AA}$ for BAK4, and the difference of refractive indices between core and cladding layers was 0.9% and 2.5%, respectively. The waveguide fabricated with the core layer of BK7 showed better optical properties when the final diffractive optical probe heads were measured with red laser(650nm) source.

• Journal of the Optical Society of Korea
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• 제14권4호
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• pp.290-297
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• 2010

The paper reviews progress and future prospects of two kinds of planar waveguide devices; they are (a) silica and silicon photonics multi/demultiplexers for communications and signal processing applications, and (b) a novel waveguide spectrometer based on Fourier transform spectroscopy for sensing applications.

• 한국세라믹학회지
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• 제37권6호
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• pp.524-529
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• 2000

Silica slab wavegudie was fabricated on Si substrates by FHD for planar optical passive devices. The slab waveguide consists of lower clad and core layers, where core layer index is controlled by GeO2 addition. Doping of GeO2 in silica is difficult because of the low deposition density due to nonspherical particle generation in FHD process. Silica core particles deposited at various conditions such as flame temperature and substrate scanning were analyzed by SEM and TEM. As the flame temperature increased, the surface roughness of the core layer was decreased up to 3.6 nm after consolidation. Index difference and thickness of core of slab waveguide were 0.3%, 8$\mu\textrm{m}$ respectively. Measured optical loss at TE mode was <0.04 dB/cm at 1.3$\mu\textrm{m}$ and <0.06 dB/cm at 1.55$\mu\textrm{m}$.

• E2M - 전기 전자와 첨단 소재
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• 제11권11호
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• pp.53-65
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• 1998

Planar lightwave circuits (PLCs) provide various important devices for optical wavelength division multiplexing (WDM) systems, subscriber networks and etc. This paper reviews the recent progress and future prospects of PLC technologies including arrayed-waveguide grating multiplexers, optical add/drop multiplexers, programmable dispersion equalizers and hybrid optoelectronics integration technologies.

• ETRI Journal
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• 제25권2호
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• pp.73-80
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• 2003

This paper describes an effective method for forming silicon oxide on silica-on-silicon platforms, which results in excellent characteristics for hybrid integration. Among the many processes involved in fabricating silica-on-silicon platforms with planar lightwave circuits (PLCs), the process for forming silicon oxide on an etched silicon substrate is very important for obtaining transparent silica film because it determines the compatibility at the interface between the silicon and the silica film. To investigate the effects of the formation process of the silicon oxide on the characteristics of the silica PLC platform, we compared two silicon oxide formation processes: thermal oxidation and plasma-enhanced chemical vapor deposition (PECVD). Thermal oxidation in fabricating silica platforms generates defects and a cristobalite crystal phase, which results in deterioration of the optical waveguide characteristics. On the other hand, a silica platform with the silicon oxide layer deposited by PECVD has a transparent planar optical waveguide because the crystal growth of the silica has been suppressed. We confirm that the PECVD method is an effective process for silicon oxide formation for a silica platform with excellent characteristics.

• 한국광학회:학술대회논문집
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• 한국광학회 2006년도 동계학술발표회 논문집
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• pp.149-150
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• 2006

• ETRI Journal
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• 제26권6호
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• pp.661-664
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• 2004

The thermal behavior of an arrayed-waveguide grating made of a silica/polymer hybrid waveguide was examined. We experimentally confirmed that the hybrid waveguide is effective to decrease the temperature and polarization dependence of the center wavelength owing to the negative thermo-optic coefficient of the refractive index and extremely low baking temperature of the polymer cladding. However, the detachment of the polymer cladding from the silica core, which took place either during a repeated heat cycle test or during long-term storage in atmosphere, was a serious problem for practical use.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 디스플레이 광소자 분야
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• pp.105-108
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• 2002

We report on the polarization-insensitive design and fabrication of an arrayed waveguide gratings (AWG's) using sol-gel derived silica glass films formed on fused silica substrates to provide cheap and stable tools for better design. An arrayed-waveguide grating multiplexer with raised structure is fabricated in order to effect polarization sensitivity. Since polarization is usually not known after propagation in an optical fiber. passive WDM components such as monolithic wavelength demultiplexer have to be polarization insensitive. Here, we observed that polarization have effect on crosstalk of output spectrum in arrayed-waveguide grating

• 한국광학회지
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• 제14권2호
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• pp.135-141
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• 2003

양의 열광학 계수를 갖는 실리카를 하부클래드 및 코아에 그리고 음의 열광학 계수를 갖는 폴리머를 상부클래드에 적용한 AWG(Arrayed Waveguide Grating) 파장분할 다중화 소자에 대하여 이차원 스칼라 유한차분법(Scalar Finite Difference Method; SFDM)으로 온도의존 특성을 분석한 결과, 클래드의 굴절률을 변화시키거나 실리카 코어 상부에 실리카 박막이 존재하는 구조에서 박막의 두께를 변화시켜 온도의존 특성을 조절할 수 있음을 확인하였다. 이러한 해석결과에 근거하여 폴리머 상부클래드가 적용된 AWG 소자를 제작하였으며 기존의 실리카 AWG 소자와 특성을 비교분석하였다. 폴리머 상부클래드의 도입에 의해 삽입손실 및 크로스톡은 큰 변화가 없었으나 중심파장의 온도의존성은 0.0130 nm/$^{\circ}C$에서 0.0028 nm/$^{\circ}C$ 수준으로 감소하였다.

• Journal of Mechanical Science and Technology
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• 제15권3호
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• pp.309-319
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• 2001

This paper demonstrates the development of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include design and fabrication of the etched planar waveguide Bragg grating optical temperature sensor. The typical bandwidth and reflectivity of the surface etched grating has been ∼0.2nm and ∼9%, respectively, at a wavelength of ∼1552nm. The temperature-induced wavelength change is found to be slightly non-linear over ∼200$^{\circ}C$ temperature range. Typically, the temperature-induced fractional Bragg wavelength shift measured in this experiment is 0.0132nm/$^{\circ}C$ with linear curve fit. Theoretical models with nonlinear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance.