• 한국표면공학회지
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• 제32권3호
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• pp.461-466
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• 1999

Diamond-like carbon(DLC) films were directly deposited onto germanium(Ge) witness pieces and lenses by a capacitively coupled 13.56 MHz RF glow discharge plasma with $CH_4$ gas. The characterizations of DLC films were measured using a Raman and FTIR spectrometer. The configuration of Raman and FTIR spectra had a traditional shape. The IR transmittance was measured using an IR spectrophotometer. The maximum values of the IR transmission of Ge with the DLC/Ge/DLC, DLC/Ge/BBAR (broad band antireflection), DLC/Ge, and BBAR/Ge structures are 98%, 93%, 64%, and 63.5%, respectively, which come up to the theoretical values. The uniform DLC films were obtained by a rotation of the cathode at certain conditions.

• 대한치과기공학회지
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• 제38권3호
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• pp.193-199
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• 2016

Purpose: The purpose of this study was to know of photopolymerization effect of self-etch dual-cured resin cement on different transmittance and thickness of zirconia disks. Methods: The two types of transparent and opaque zirconia speciments were prepared. The five speciments of each groups were seperated with 0.5mm and 1.0mm thickness. Degree of conversion(DC) were studied by FT-IR spectroscopy using ATR method before and after irradidaion for 40 sec. Results: The relative DC was showed the higher results of ZS5 as compared with ZS10 (p < 0.05). And OP5 and OP10 were lower results than ZS10 (p < 0.05). Conclusion: The photopolymerization effect of dual-cured resin cement were affected by the transmittance and thickness of zirconia.

• 한국세라믹학회지
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• 제33권8호
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• pp.855-862
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• 1996

The nucleation and the crystal growth rates of Ge-Se-Te chalcogenide glass by two step heat-treatment and its effect on the mechanical optical properties and water-resistance were determined. The maximum nuclea-tion and crystal growth rate were 2.1$\times$103/mm3 .min at 28$0^{\circ}C$ and 0.4${\mu}{\textrm}{m}$/min at 33$0^{\circ}C$ respectively. When the crystal volume fraction with crystal size $1.5mutextrm{m}$ was about 4% the (hardness and fracture toughness were about 117kg/mm2 and 6.0 MPa.mm1/2)respectively. The weight loss of crystallized glass in water was lower than parent glass($25^{\circ}C$ for 32 hrs : 0.03% 8$0^{\circ}C$ for 16 hrs : 0.1%) as 0.01% at $25^{\circ}C$, 0.03% at 8$0^{\circ}C$ for 16 hrs : 0.1%) at $25^{\circ}C$ 0.03% at 8$0^{\circ}C$ respectively. The IR-transmittance decreased with increasing crystal size and crystal volume fraction. The IR-transmittance of crystallized glass with the crystal size of $1.5mutextrm{m}$ (crystal volume fraction : 4%) presented 56% which was about 4% lower than that of parent glass.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1985년도 추계학술대회 논문집
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• pp.21-23
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• 1985

By adding La$_2$O$_3$ to optical multicomponent glass composition, after making mother glass and core fiber that enable to enlarge the infrared transmittance region, then surveyed the optical properties. Through thermal analysis of the glass abstained by melt-quenching after selecting stable basic composition on devitrification and replace SiO$_2$ by 4-12wt% La$_2$O$_3$. As La$_2$O$_3$ increases up to l2wt% transition temperature, refractive index, density, deformation temperature increased, whereas thermal expansion coefficient decreased. As a result of inspectig transmittance in UV/VIS/IR region, visable region indicated the decrease of transmittance by increasing the La$_2$O$_3$ and transmittance region was enlarged by increasing the La$_2$O$_3$ in IR region. Also, fabricate core fiber at 820$^{\circ}C$ and severy the optical loss we could fact that La$_2$O$_3$ composition added 12wt% showed the minimum optical loss.

• 센서학회지
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• 제28권2호
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• pp.101-105
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• 2019

ZnS substrates with excellent transmittance in the mid-infrared region ($3-5{\mu}m$) were prepared using hot pressing instead of conventional chemical vapor deposition (CVD). Diamond-like carbon(DLC) was coated on either one or both sides of the ZnS substrates to improve their mechanical properties and transmittance. More specifically DLC was coated using CVD with an Ar and $C_2H_2$ mixed gas, and Ge was used as the bonding layer. During CVD, the bias voltage was fixed to 500 V and analyzed by Fourier transform infrared spectroscopy (FT-IR), nanoindenter, scanning electron microscope and energy dispersive spectrometry. Results of hardness analysis using the nanoindenter, showed that DLC coating increased from 5.9 to 17.7 GPa after deposition. The FT-IR spectroscopy results showed that, in the mid-infrared region ($3-5{\mu}m$), the average transmittance of the samples with DLC coating on one and both sides increased by approximately 6% and approximately 11.2% respectively. In conclusion, the DLC coating improved the durability and transmittance of the ZnS substrates.

• 한국세라믹학회지
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• 제32권6호
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• pp.697-702
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• 1995

The rough growth surfaces of diamond films fabricated by the hot filament CVD were polished using thermomechanical polishing method. And then, its application to the optical windows was discussed through the measurement of transmittance in the range of infrared radiation and analysis of surfaces structure. The results were compaerd with those of the films polished with conventional mechanicla polishing. The transmittance of the mechanically polished film reached 57~66% over the whole range from 500 to 4000 cm-1. But the transmittance of the film polished with thermomechanical polishing method was reduced below 35%. This decrease in transmittance was due to both the graphitization of diamond on the polished surface and the growth of $\beta$-SiC at diamond/Si interface during polishing. The residual Fe in hte thermomechanically polished surface was confirmed by SIMS analysis. This Fe played the role of the graphitization of near surface region of the diamond film.

• 한국세라믹학회지
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• 제39권2호
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• pp.210-215
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• 2002

본 연구에서는 $CO_2$ 흡수단이 있는 4.3${\mu}m$ 파장대역의 광학 필터를 전자빔 증발 장치를 이용하여 Ge와 $SiO_2$ 박막을 다층으로 설계, 제작하였다. 제작된 Ge/$SiO_2$ 다층박막 필터는 기준파장에 대하여 반가폭(FWHM) 204nm, 투과율 58.2%, 금지대역에 대하여 5% 이하의 차단특성을 나타내는 협대역 투과필터 (narrow band-pass filter: BPF)특성을 나타내었다. 광학적 대역투과필터를 사용하여, FT-IR내에 감지실을 설치하여 단식 필터(KBr+BPF)와 복식필터(BPF+BPF)의 $CO_2$ 농도별 감도특성을 비교측정 하였다. 측정시 $CO_2$의 농도는 500ppm을 단위로 500∼5000ppm의 범위까지 관찰하였는데, 복식 필터는 단식 필터에 비해 투과율이 낮았지만, 우수한 감도 특성을 보였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.244.1-244.1
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• 2015

The Ag Nanowire is one of the materials that are widely studied as alternatives to ITO and is available for large area, low cost process and the flexible transparent electrode. However, Ag nanowire can have the problem of a lack of stability at high temperatures, making this impossible to form a film. Using a structure of ITO/AgNW/ITO in photodetector device, we improved the properties of the ITO in the IR region and improved the thermal stability of the AgNW. The structure of ITO/AgNW/ITO has a high transmittance value of 89% at a wavelength of 900 nm and provide a good electrical property. The AgNWs embedded ITO film has a high transmittance, this is because of the light scattering from the AgNW. The thermal stability of the developed ITO/AgNWs/ITO films were investigated and found AgNWs embedded ITO films posses considerable high stability compared to the solo AgNWs on the Si surface. The ITO/AgNWs/ITO device showed a improved photo-response ratio compared to those of the conventional TC device in IR region. This is attributed to the high transmittance and low sheet resistance. We suggest an effective design scheme for IR-sensitive photodetection by using an AgNW embedded ITO.

• 한국광학회지
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• 제35권1호
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• pp.24-29
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• 2024

본 연구에서는 나노패턴된 금속(Ag)-유전체(PDMS) 다층 기반의 쌍곡선 메타구조를 제안하고 영상 소자용 적외선 차단 필터의 성능에 대해 보고한다. 사각형 모양의 Ag 나노 패턴의 크기와 Ag 나노 패턴을 둘러싼 PDMS의 두께를 최적화함으로써, 제안된 IR 차단 필터가 0.70-1.01 ㎛ 파장 대역의 빛을 99% 차단하면서도 가시광 영역에서 94% 이상의 높은 투과율을 나타냄을 보였다. 차단 파장 대역은 쌍곡선 메타구조의 epsilon-near-zero 파장보다 긴 파장 영역에서 시작하여 Ag 나노 패턴에 의한 플라즈모닉 흡수가 강한 지점에서 끝나게 된다. 근적외선 차단 대역보다 긴 파장 영역에서는 수평으로 인접한 Ag 나노패턴들 사이의 플라즈모닉 커플링 효과로 다시 투과도가 증가됨을 알 수 있다. 이러한 메타구조체는 적외선 차단 필터의 성능을 향상시킬 수 있을 뿐만 아니라 공정 단순화를 통해 초박형 제조가 가능하여, 다양한 평면 광학 및 집적광학 부품들에 적용될 수 있다.

• 한국진공학회지
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• 제10권2호
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• pp.194-200
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• 2001

13.56 MHz rf플라즈마를 이용하여 증착된 DLC(diamond-like carbon) 박막의 광학적 특성에 대해 조사하였다. $CH_4$가스를 원료가스로 하여 PECVD법에 의해 DLC 박막을 형성하였으며 이때 RF power, working pressure, 보조가스의 종류 및 양에 따른 투과도(transmittance)와 optical band gap의 변화를 관찰하였다. RF power가 증가하고 working pressure가 높을수록 optical band gap이 감소하는 결과를 얻을 수 있었고. FT-IR분석을 이용하여 탄소-수소 결합 양을 관찰함으로써 DLC 박막의 결합구조 변화를 증명할 수 있었다. 그리고 수소와 질소를 첨가한 경우 증착시 탄소-수소 결합을 끊는 역할을 하여 optical band gap이 감소하는 결과를 얻을 수 있었다.