• 한국광학회지
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• 제9권3호
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• pp.156-161
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• 1998

에어로졸 화염증착법을 개발하고 이 방법을 써 실리콘 기판 위에 Pyrex 무응력 도피박막으로 제작하였다. 파이렉스 도파 박막계의 굴절률은 조절하기 위하여 지르코늄을 첨가하였으며, 지르코늄 함량이 0wt%부터 3wt5까지 변하는 경우 굴절률이 1.460부터 1.475까지 변화하였다. 파이렉스 도파로의 평판도파로형 광증폭기에 응용 가능성을 보기 위하여 어븀을 첨가하여보았으며 어븀 함량이 0wt%부터 1wt% 까지 변하는 경우 박막의 굴절률이 1.460부터 1.465 까지 변화함을 확인하였다. 프리즘 커플러를 써서 제작된 도피피막에 과을 여기시킨 결과 광집적회로에 응용이 가능한 수준의 투과성이 우수한 박막임을 확인하였다. 파이렉스 도피피막의 편광 변화에 따른 박막굴절률의 변화는 2$\times$104이하로 측정되었다.

• 한국레이저가공학회지
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• 제8권1호
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• pp.9-18
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• 2005

The laser direct writing method using a UV Argon-ion laser is studied for fabrication of waveguide. The laser direct writing system is constructed with a vision camera, a xy-stage, a motion controller and the delivery components of a laser beam. The UV Argon-ion laser has wavelength range of $333.6\~363.8$ nm. A photo-active UV curable polymer for a planar light-wave circuit(PLC) of single mode is used. This polymer is irradiated by Argon-ion laser and developed by a solvent after a post-baking. The optimum laser direct writing condition is obtained experimentally by changing various process parameters such as laser power, writing speed and focal length. The propagation and coupling loss of a optical waveguide was measured as 1dB/cm and 0.6dB/cm, respectively. Also, the minimum width of waveguide of $100{\mu}m$(ZPLW-207) is obtained. Finally, the waveguides of line, bend and branch type are successfully fabricated.

• 한국통신학회논문지
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• 제28권9A호
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• pp.754-762
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• 2003

3차원 FD-BPM 기법을 이용하여 완전도체면 아래의 유전체와 측면 연마된 광섬유의 소산장 결합 및 전파특성에 대한 해석 연구 결과를 나타내었다. 3차원 FD-BPM 기법을 사용하기 위한 해석 구조의 구성과 적용 방법을 설명 하였으며 완전 도체를 가지는 비대칭 무한 평면 도파로와 광섬유의 코어의 굴절률 차이에 따른 결합 특성 및 필드의 분포를 나타내었다. 그리고 일반적인 대칭 및 비대칭 무한 평면 도파로와 측면 연마된 광섬유와의 결합 및 전파 특성과 서로 비교 분석하여 그 특징을 나타내었다.

• Journal of the Optical Society of Korea
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• 제7권1호
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• pp.20-27
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• 2003

A theoretical presentation of evanescent coupling is offered with respect to the refractive indexes between a side-polished optical fiber and an infinitely planar waveguide with a conductor cladding (PWGCC). The PWG is suspended at a constant distance from an unclad fiber core and attached with the perfect conductor (PEC) on one side. The behavior of the distributed couple. is examined using a coupled mode model, which takes account of the two dimensions of the waveguide configuration. The coupling and propagation of light were found to depend on both the relationship between the refractive index values of each structure and the configuration of the side-polished fiber used in the PWGCC. The spreading of light in the unconfined direction of the PWGCC is described in terms of a simple geometrical interpretation of the synchronization condition that is in agreement with a previous investigation of the problem based on the coupled-mode theory (CMT). The power of the light propagation in the fiber decreased exponentially along the fiber axis as it was transferred to the PWGCC, where it was carried away.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1749-1752
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• 2007

The Near to Eye Display (NED) solves the problem of having a display larger than a small portable device. The virtual image of the NED is created using a microdisplay and imaging optics. It is important that the optics does not interfere with the human visual system and that the device is light, compact and easy to wear. In this paper the principles of a biocular NED, which is based on a novel diffractive Exit Pupil Expander (EPE), are presented. The optical system is compact and intrinsically free from distortions and misalignments.

• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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• pp.156-157
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• 2000

The amplification method using evanescent wave coupling has a long history and has been widely used as a new lasing method, especially, in the waveguide optics$^{(1)}$ . In particular, it has been observed experimentally that when the light wave propagating in a dielectric medium is totally reflected at the planar interface between the dielectric and a pumped active medium, the reflectance may be greater than unity, i.e., amplification is possible$^{(2)}$ . There were several attempts by other authors to explain this enhanced internal reflection (EIR) classically$^{(3)}$ . They commonly introduced a complex refractive index for the active medium with its imaginary part being negative, and this scheme was also used to describe an amplification process in a waveguide having active-cladding region$^{(4)}$ . However these theories are phenomenological, using macroscopic constants, and therefore a microscopic theory is needed to understand EIR in a fundamental level. (omitted)

• 대한전자공학회논문지
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• 제25권3호
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• pp.343-351
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• 1988

Planar optical waveguides are fabricated on a Y-cut LiNbO3 single crystal substrate by Ti indiffusion method. From data measured by the bright M-line spectroscopy, refractive index profiles are reconstructed by WKB approximation method. Then, single strip, X-crossing strip, and Y-brinch strip optical waveguides are fabricated on X-cut LiNbO3 single crystal substrate, with waveguide patterns made by the laser beam direct writing method. And their near-field intensity profiles are observed after coupling the light to the waveguide edges.

• 한국전기전자재료학회논문지
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• 제11권9호
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• pp.739-745
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• 1998

The objective of this paper is to provide experimental data of Er(rare- earth)doped $SiO_2$thin film made by sputtering methods. The deposition rate of silica glass by sputtering method was 55$\AA$/min. In EDD measurements, the average Er concentration in the deposited film was 0.77(wt%). After annealing at $900^{\circ}C$, the Cl concentration decreased from 3.79(wt%) to 1.52(wt%). The refractive indices of the core $n_1$, cladding $n_2$ were 1.458, 1.558 respectively at 632.8 nm. The refractive index difference between core and cladding, $\Delta$n was 0.1. The refractive index profile of core and cladding interface shows step profile. In the study, $SiO_2$ glass films of Si wafer were successfully doped with active erbium. Therefore, this experimental data will be applicable for fabrications of Er doped planar integrated optical device.

• Journal of the Optical Society of Korea
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• 제7권3호
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• pp.180-187
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• 2003

A theoretical presentation by using a three-dimensional finite difference beam propagating method (3-D FD-BPM) for the evanescent coupling is offered with respect to the refractive indexes between a side-polished optical fiber and an infinitely planar waveguide with a conductor cladding (PWGCC). The PWG is suspended at a constant distance from an unclad fiber core and attached with a perfect conductor (PEC) on one side. The coupling and propagation of light are found to depend on both the relationship between the refractive index values of two structures and the configuration of the side-polished fiber used in the PWGCC. The spreading of light in the unconfined direction of a PWGCC is presented with the distribution of electric fields in xy - plane and the absolute amplitude of electric fields along the x and y axis. The power of the light propagation in a fiber decreases exponentially along the fiber axis as it is transferred to the PWGCC, where it is carried away.

• 한국통신학회논문지
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• 제28권2A호
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• pp.70-79
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• 2003

완전도체면 아래의 유전체와 측면 연마된 광섬유의 소산장 결합 및 전파특성에 대한 해석 연구 결과를 나타내었다. 두 구조에서의 전파특성과 소산장 결합 관계를 해석하기 위해 결합모드 방정식과 혼합 모드(compound-mode) 방정식을 이용하여 코아와 유전체의 굴절률 및 구조의 각 변수에 대한 특성을 나타내었다. 그리고 측면 연마된 광섬유와 완전도체면 아래의 유전체가 결합할 때 일어나는 광섬유에서의 감쇠현상을 비교하기 위하여 감쇠상수를 구하여 함께 비교하였다.