• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.98-99
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• 2000

코어 가까이 측면 연마한 광섬유를 이용하여 광 여파기, 편광기, 감쇠기등의 광통신 소자로 응용하고자 하는 연구가 많이 진행되고 있다.$^{[1]}$ 이 소자는 광섬유를 절단하지 않은 상태에서 코어 가까이 측면 연마하여 광학적 기능을 가진 소자를 제작함으로서 공정이 간단하고 삽입손실이 작은 특성을 가지며 기계적 신뢰성이 우수하다. 측면 연마된 광섬유를 이용한 광 증폭의 경우 광섬유의 소산장(evanescent field)과 펌핑광에 의해서 여기되는 활성 물질과의 상호작용에 의해서 광 이득을 얻는다. 소산장 결합에 의한 평면도파로에서의 광 증폭$^{[2]}$ 과 다중 모드 광섬유에서의 펄스 레이저 증폭, 단일 모드 광섬유에서 632.8nm He-Ne 레이저의 연속광원 증폭$^{[3]}$ 은 이미 보고되었다. 본 논문에서는 측면 연마된 다중 모드 광섬유의 연마된 부위에 색소가 첨가된 용액을 떨어뜨림으로서 발생하는 소산장 결합에 의해서 광섬유내를 진행하는 연속적인 He-Ne 레이저 광을 증폭시키는 방법을 제안하고자 한다. (중략)

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.754-762
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• 2003

The coupled and propagated property of the composite side-polished fiber and infinite planar waveguide with conductor cladding (PWGCC) is presented by using the 3-D finite difference beam propagating method (FD-BPM) in according to the variety of refractive indexes between the fiber and the infinite planar waveguide. It is also introduced for the technique to be applied at and consisted of the analysis domain of 3-D FD-BPM for the coupling between the side-polished fiber and PWG. It is also compared the properties of coupling between the side-polished fiber and PWGCC with them of the general symmetric and asymmetric PWG without perfect conductor (PEC), which has been investigated by many researcher.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.138-139
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• 2000

광섬유-평면도파로 결합기는 측면 연마된 광섬유와 그 위에 올려진 평면도파로 사이의 소산장 결합(evanescent field coupling)를 이용하는 소자이다. 이 결합기는 기본적으로 파장선택성과 편광선택성을 있고, 삽입손실이 매우 작고 기계적 신뢰성이 우수하여 많은 주목을 받아 왔다. 평면도파로의 재료로 반도체, 크리스탈, 액정크리스탈, 폴리머등 다양한 물질이 이용될 수 있어 광통신뿐만 아니라 광 센서 분야에서 활발하게 연구되어 왔다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.50-51
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• 2002

측면 연마된 광섬유 표면 위에 새로운 물질층을 형성시킨 후 광섬유 모드의 소산장(evanescent field) 결합을 유도하여 다양한 능동 및 수동 광섬유로 응용이 가능하다. 광섬유를 연마하기 위하여 쿼츠에 형성된 홈에 광섬유를 에폭시로 고정시키고 쿼츠와 함께 광섬유 클래딩을 연마하는 방법이 잘 알려져 있다. 이러한 방법은 측면 연마된 광섬유를 연마하는데 다소 긴 시간이 필요하다. 본 논문은 광섬의 클래딩을 연마휠로 제거하는 기법을 소개하고 연마된 광섬유의 클래딩 위에 금속이나 유전체층을 결합하여 기능성 광섬유 소자를 제작할 수 있음을 보인다. (중략)

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2A
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• pp.70-79
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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 coupler 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 synchromization 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.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.2
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• pp.33-38
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• 2004

We have demonstrated a tunable Inter based on an asymmetric directional coupler made of a side-polished polarization maintaining fiber coupled with a polymer planar waveguide. The thermo-optic effects of the polymer planar waveguide induced by a micro-strip heater placed on the top layer of the device leads to shift of resonance wavelength of the coupler. The fabricated device exhibited wide tunable range exceeding 230 nm with 720 ㎽ of applied electrical power.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.7
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• pp.42-49
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• 1999

In this paper, we proposed a simple measurement method to find the behaviors of the fiber-to-waveguide coupler. The polished fiber blocks and planar waveguides on silicon dioxide were fabricated independently and then optically coupled by physical pressure. Several kinds of polymer with different refractive indices were used for waveguide films. The proposed method makes it possible to measure the center wavelength, bandwidth, extinction ratio, and polarization dependence of the coupler during fabrication procedure. The wavelength sensitivity increased with refractive index of polymer. The symmetric planar waveguide structure and isotropic property of guiding materials reduced polarization dependent property. Insertion loss of the coupler was less than 0.5dB. It is expected that our measurement method is useful for developing various optical devices using evanescent coupling between polished fiber and planar waveguide such as optical modulators and filters etc.

• Korean Journal of Optics and Photonics
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• v.15 no.3
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• pp.222-228
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• 2004

The variable optical attenuator based on side polished fiber technique was experimentally demonstrated. Various combination mixtures of poly(vinylidene fluoride) and poly(methyl methacrylate) have been used as the overlay waveguide materials for the variable optical attenuator application. A controllable amount of optical power can be extracted via evanescent coupling by changing the temperature of the polymer mixture, thereby changing its refractive index. The VOA under test provides a maximum attenuation of 30 ㏈ and an insertion loss of 0.1 ㏈.

• Journal of Sensor Science and Technology
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• v.13 no.3
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• pp.207-212
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• 2004

We have investigated the optical characteristics of a directional coupler made of a side-polished polarization maintaining fiber in contact with a multimode planar waveguide and its applications as sensors. A device structural condition to achieve the polarization insensitive wavelength response has been presented. The fabricated devices revealed a superior immunity to the bending and the deformation of PM fibers in the input section. It is experimentally shown that the proposed device is suitable for a remote fiber sensor.

• Korean Journal of Optics and Photonics
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• v.10 no.5
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• pp.419-423
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• 1999

Optical filters utilizing the evanescent filed coupling between the side polished fiber and polymer planar waveguide were fabricated and optical properties of the devices were measured. A scheme for reducing polarization dependent properties of the device was proposed and demonstrated experimentally. Our measurement results showed that resonance wavelengths and filtering depth of the optical filters can be determined by adjusting thickness of planar waveguide and polishing depth of the fiber. The device fabrication procedure including fiber polishing steps and formation of polymer planar waveguide were described. The optical characteristics of fabricated optical filers were that 3 dB bandwidth was 15 nm, the resonance wavelength difference between the TE and TM polarized response was less then 2 nm, and insertion loss was less then 0.2 dB. The measured resonance wavelength drift dut to the variation of ambient temperature was -0.35 nm/$^{\circ}C$.