플라스틱 광섬유 측면 발광 광원을 이용한 도광판의 성능 평가

이승석,마혜준,신용진,최은서 한국물리학회 2012 새물리 Vol.62 No.9

In this study, light emission induced from side illumination of a plastic optical fiber was used as a light source for a conventional liquid crystal display, and the feasibility of using the fiber as a light source for a display was demonstrated. Before experimental implementation, a specific pattern was made to extract light from the plastic optical fiber. Simulation results showed overall uniform light illumination at P-type, where P-4 presented the most uniform distribution. Also, the O-1 pattern among O-type patterns resulted in the highest illumination of 0.4358 cd/cm^2. Based on these results, some types of P-type patterns were implemented in the plastic optical fiber by using a CO_2 laser. The prepared laser-processed plastic optical fiber was applied to a light guide panel as a light source, and the light illumination performance of the light guide panel was measured. From the measurement results,the plastic optical fiber having a P-4 pattern provided the best uniform illumination 59% when it was used as the light source. The experimental results demonstrated that the plastic optical fiber could be applied as an alternative to a conventional light source for liquid crystal displays by adjusting the pattern distance and depth. 본 연구는 플라스틱 광섬유의 측면발광을 유도하여 방출되는 광을도광판에 광원으로 적용함으로써 기존 액정 디스플레이의 대안광원으로써의 가능성을 알아보고자 하였다. 실험에 앞서 플라스틱광섬유의 측면부분에 특정한 패턴을 일정한 간격으로 패턴을 생성하였다. 이 패턴은 코어 안에 전파되는 광을 광섬유 측면으로 유도하기 위한것으로 이 상황을 전산모사를 통해서 예측해 보았다. 그 결과 전체적으로균일한 휘도분포를 P-타입에서 볼 수 있었으며 특히 P-4에서 가장 균일한휘도분포를 얻을 수 있었다. 또한 O-타입 중에서는 O-1에서 가장 높은휘도값(0.4358 cd/cm^2)을 얻을 수 있었다. 이러한 결과를 바탕으로P-타입 일부를 CO_2레이저를 이용하여 플라스틱 광섬유에 직접가공하였다. 이렇게 가공된 플라스틱 광섬유를 도광판에 광원으로적용하여 휘도 특성을 측정하였다. 측정결과 도광판에 적용한 P-4에서가장 균일한 휘도분포(59%)를 얻을 수 있었다. 본 실험을 통하여플라스틱 광섬유 광원의 발광 특성을 특정패턴의 간격과 깊이 조절을통해 제어가 가능함을 알 수 있었으며, 도광판 광원으로써의 가능성을확인할 수 있었다.

플라스틱 광섬유 굽힘 손실 및 광 조도 분포에 관한 연구

박형주(Hyoung Joo Park),김대현(Dae-Hyun Kim) 한국비파괴검사학회 2021 한국비파괴검사학회지 Vol.41 No.3

플라스틱 광섬유(plastic optical fiber, POF)는 유리 광섬유보다 높은 내구성을 가지고 있으며, 또한 다루기 쉽다는 장점을 가지고 있다. 본 연구는 이러한 장점을 가진 계단형 굴절률 기반 플라스틱 광섬유를 이용한 센서 제작에 도움이 되고자 진행되었다. 특히 굽힘으로 인한 광 손실 및 광섬유 간 거리에 따른 광손실을 이용한 센서를 설계하고자 할 때 이론적으로 광 손실을 증명하고자 진행되었다. 이를 위해 본 논문은 플라스틱 광섬유 굽힘 손실 및 계단형 굴절률 기반 플라스틱 광섬유의 투광 조도분포 이론을 정리하였고, 플라스틱 광섬유의 광 손실 연구를 직접 진행하였다. 광 손실 연구는 두 가지 방법으로 진행되었다. 첫 번째로, 플라스틱 광섬유의 굽힘을 통한 광 손실 측정 연구를 통해 곡률 반경과 광 손실의 관계를 확인하였다. 두 번째로, 진행한 연구는 절단된 플라스틱 광섬유를 이용하여 광섬유 거리 간의 광 손실 연구를 진행하고 이를 통해 광 조도 분포 데이터를 정량화하였다. Plastic optical fiber (POF) has higher durability than glass fibers, and the advantage of being easy to handle. This study is intended to aid in the development of sensors using step-index multimode plastic optical fiber with these advantages. In particular, when we wanted to design sensors using light loss owing to bending and the distance between fiber optics, we proceeded to theoretically prove light loss. Therefore, this paper summarizes the theory of the loss of plastic fiber bending and the floodlight distribution of stepped refractive index-based plastic fiber, and proceeds directly with the study of the light loss of plastic fibers. The study on light loss was conducted in two ways. First, the relationship between the curvature radius and light loss was confirmed by studying the light loss caused by the bending of plastic optical fiber. Second, the study conducted a light loss study between fiber distances using cut plastic fiber, which quantifies the light intensity distribution data.

유연 광섬유 기술을 적용한 의류 제품용 로고 디자인 방향의 제시

김남희 ( Nam Hee Kim ),양진희 ( Jin Hee Yang ),홍순교 ( Soon Kyo Hong ),홍석일 ( Suk Ii Hong ),이주현 ( Joo Hyeon Lee ) 한국감성과학회 2012 감성과학 Vol.15 No.4

The purpose of this study is to derive design guideline for logo design development of smart clothing using flexible plastic optical fiber. In a criterion of guideline derivation for logo design, the first, it is a question of whether it indicates an appropriate degree of brightness across the front of flexible plastic optical fiber. The second, it is a question of whether it indicates relatively an uniform brightness characteristic across the front of flexible plastic optical fiber. For this, the brightness characteristic of flexible plastic optical fiber according to the angle changes and the length of flexible plastic optical fiber was analyzed by the ``Experiment 1``. To deduce guideline for the logo design of the actual garment, the brightness characteristic of flexible plastic optical fiber about the main morpheme of the capital letter of alphabet was analyzed by the ``Experiment 2``, Based on the results of the two experiment, this study derived design guideline and limitations for logo design of smart clothing visualized by the flexible plastic optical fiber.

Development of Nasal-cavity- and Abdomen-attached Fiber-optic Respiration Sensors

유욱재,장경원,이봉수,서정기,허지연,문진수,박장연 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.61

In this study, we fabricated two types of optical-fiber-based sensors for non-invasive respiratory monitoring. A nasal-cavity-attached respiration sensor can measure the temperature variations of airflow by using a silver-halide optical fiber located in the nasal-cavity, and an abdomen-attached respiration sensor can measure the changes in the abdominal circumference by using a plastic optical fiber. We measured the modulated light beams that are guided to the detectors via optical fibers due to the airflow and to the abdominal movement. In addition, the respiration signals from the fiber-optic respiration sensors are compared with those from the BIOPAC® system.

Side-Coupled Asymmetric Plastic Optical Fiber Coupler for Optical Sensor Systems

Kwang Taek Kim,Deok Gi Kim,Woong Keun Hyun,Ki Bum Hong,임기건,Se-Jong Baik,Dae-kyong Kim,Hyun-yong Choi 한국광학회 2008 Current Optics and Photonics Vol.12 No.4

This paper reports a side-coupled asymmetric 1×2 plastic optical fiber coupler for an optical sensor system. The dependence of the optical power coupling ratio on the coupling angle and refractive index of the adhesion layer in both the forward and backward directions was examined based on the geometrical optics. It was confirmed experimentally that the coupling ratios can be optimized by controlling the coupling angle and refractive index of the adhesion layer. A maximum forward coupling efficiency > 93% was achieved.

플라스틱 광섬유의 손실 특성을 이용한 무선잡음광의 영향 감소

이성호,Lee Seong-Ho 한국전자파학회 2005 한국전자파학회논문지 Vol.16 No.7

본 논문에서는 무선광 연결에서 신호광과 잡음광에 대한 플라스틱 광섬유의 손실차를 이용하여 잡음광의 영향을 감소하였다. 플라스틱 광섬유에서 신호광과 잡음광에 대한 손실계수가 달라서 차동검출기를 구성하는 2개의 포토다이오드로 연결되는 광섬유의 길이를 다르게 하면 신호광과 잡음광에 대한 감소 비율이 달라져 변별소자의 역할을 한다. 따라서 별도의 광필터를 설치하지 않아도 잡음광의 간섭을 소거하고 신호성분을 검출할 수 있다. 광섬유를 사용하지 않는 단일의 포토다이오드를 사용할 때에 비하여 광섬유를 사용할 때 약 9.7 dB신호대 잡음비를 개선하였다. In this paper, optical noise effect is reduced by using the loss characteristics of plastic fibers in an optical wireless system. The attenuation coefficient of a plastic fiber for the signal is different from that f3r the noise light, and the length difference between two fibers to the 2PD's behaves like a discriminative element. It is possible to eliminate the optical noise effect and detect only the signal without optical filters. The signal to noise ratio in a differential detector using fibers was 9.7 dB higher than in a single photodiode without optical fiber.

플라스틱 광섬유를 이용한 호흡센서의 개발

유욱재,백지윤,조동현,장경원,서정기,허지연,이봉수,조영호,박병기,문주현,Yoo, Wook-Jae,Baek, Ji-Yun,Cho, Dong-Hyun,Jang, Kyoung-Won,Seo, Jeong-Ki,Heo, Ji-Yeon,Lee, Bong-Soo,Cho, Young-Ho,Park, Byung-Gi,Moon, Joo-Hyun 대한의용생체공학회 2009 의공학회지 Vol.30 No.6

In this study, we fabricated a plastic optical fiber based sensor which can monitor the respiration of a patient. The circumference changes of the abdomen were measured using a mirror, a light source and optical detectors because the circumferences of the abdomen could be varied with respiration. The intensity of the reflected lights were measured according to the changes of distance between mirror and plastic optical fiber connected to a light source and a photodiode-amplifier system using a Y-coupler. The respiration signals of fiber-optic sensor system were compared with those of the respiratory and temperature transducers of the $BIOPAC^{(R)}$ system. It is expected that a fiber-optic respiration sensor could be developed for real time respiration monitoring during MRI procedure based on this study.

Performance evaluation of soil-embedded plastic optical fiber sensors for geotechnical monitoring

Cheng-Cheng Zhang,Hong-Hu Zhu,Bin Shi,Jun-Kuan She,Dan Zhang 국제구조공학회 2016 Smart Structures and Systems, An International Jou Vol.17 No.2

Based on the distributed fiber optic sensing (DFOS) technique, plastic optical fibers (POFs) are attractive candidates to measure deformations of geotechnical structures because they can withstand large strains before rupture. Understanding the mechanical interaction between an embedded POF and the surrounding soil or rock is a necessary step towards establishing an effective POF-based sensing system for geotechnical monitoring. This paper describes a first attempt to evaluate the feasibility of POF-based soil deformation monitoring considering the POF–soil interfacial properties. A series of pullout tests were performed under various confining pressures (CPs) on a jacketed polymethyl methacrylate (PMMA) POF embedded in soil specimens. The test results were interpreted using a fiber–soil interaction model, and were compared with previous test data of silica optical fibers (SOFs). The results showed that the range of CP in this study did not induce plastic deformation of the POF; therefore, the POF–soil and the SOF–soil interfaces had similar behavior. CP was found to play an important role in controlling the fiber–soil interfacial bond and the fiber measurement range. Moreover, an expression was formulated to determine whether a POF would undergo plastic deformation when measuring soil deformation. The plasticity of POF may influence the reliability of measurements, especially for monitored geo-structures whose deformation would alternately increase and decrease. Taken together, these results indicate that in terms of the interfacial parameters studied here the POF is feasible for monitoring soil deformation as long as the plastic deformation issue is carefully addressed.

투명 에폭시와 광섬유를 이용한 방사선량 측정용 유기섬광체 센서 개발

박찬희,서범경,이동규,이근우 한국방사성폐기물학회 2009 방사성폐기물학회지 Vol.7 No.1

Remote detecting system for a radiation contamination using a plastic scintillator and an optical fiber was developed. Using a commercially available silica optical fiber and a plastic scintillator, we tested then for a real possibility as a remote monitoring detector. Also, a plastic scintillator was developed by itself, and evaluated as a radiation sensor. The plastic scintillator was made of epoxy resin, a hardener and an organic scintillation material. The mixture rate of the epoxy resin, hardener and organic scintillator was fixed by using their emission spectrum, transmittance, intensity etc. In this study, in order to decrease the light loss of an incomplete connection between an optical fiber and a scintillator, the optical fiber was inserted into the scintillator during the fabrication process. The senor used a plastic optical fiber and was estimated for its detection efficiency by an optic fiber's geometric factor. 방사선량 측정을 위하여 섬광체와 광섬유를 이용한 원격 측정용 센서를 개발하였다. 유리 광섬유와 상용화된 플라스틱섬광체로 원거리 측정 가능성을 시험하였고, 에폭시 수지로 자체 개발한 섬광검출소재로 방사선 측정센서로써의 성능을 평가하였다. 에폭시 수지와 유기섬광물질의 배합별 물질 특성을 측정하여 최적의 조건을 도출하였다. 광섬유와 섬광체를 연결할 때, 불완전한 접속으로 인한 광 손실을 줄이기 위하여 섬광검출소재 제조 과정 중 소재내로 광섬유를 삽입하여 일체형으로 센서를 제조하였다. 일체형 센서는 유리광섬유의 단점을 보완하여 플라스틱 광섬유를 적용하였으며, 방사선 반응 체적별 검출효율을 평가하기 위하여 검출소재 밑단으로부터 일정 거리의 광섬유를 배치하여 측정하였다. 개발한 방사선 검출용 센서는 오염도 원거리 측정뿐만 아니라 측정센서로써의 적용도 가능할 것으로 예상된다.

Development of Respiration Sensors Using Plastic Optical Fiber for Respiratory Monitoring Inside MRI System

유욱재,장경원,서정기,Ji Yeon Heo,Jin Soo Moon,Jang-Yeon Park,이봉수 한국광학회 2010 Current Optics and Photonics Vol.14 No.3

In this study, we have fabricated two types of non-invasive fiber-optic respiration sensors that can measure respiratory signals during magnetic resonance (MR) image acquisition. One is a nasal-cavity attached sensor that can measure the temperature variation of air-flow using a thermochromic pigment. The other is an abdomen attached sensor that can measure the abdominal circumference change using a sensing part composed of polymethyl-methacrylate (PMMA) tubes, a mirror and a spring. We have measured modulated light guided to detectors in the MRI control room via optical fibers due to the respiratory movements of the patient in the MR room, and the respiratory signals of the fiber-optic respiration sensors are compared with those of the BIOPAC® system. We have verified that respiratory signals can be obtained without deteriorating the MR image. It is anticipated that the proposed fiber-optic respiration sensors would be highly suitable for respiratory monitoring during surgical procedures performed inside an MRI system.