• 마이크로전자및패키징학회지
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• 제21권1호
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• pp.25-29
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• 2014

본 연구에서는 기존의 PCB의 한계를 극복할 수 있는 광 PCB에 대한 연구를 수행하였으며, 고효율 수동정렬을 위한 플러거블 렌즈구조를 제안하였다. 제안된 구조는 광 도파로 수동 정렬시 발생할 수 있는 렌즈와 도파로 간의 정렬 오차를 개선하고자 도파로와 렌즈를 합한 형태이다. 또한 탈착에 의해 손상되는 렌즈표면을 보호하기 위한 보호벽 형태를 지님으로써, 고효율의 수동정렬이 가능하게 하였다. 최적화 시뮬레이션을 통하여 구조를 설계하였고, 반복적 포토 리소그래피와 열적 리플로우 공정을 통하여 플러거블 렌즈 구조 제작을 위한 공정 연구를 수행하였다. 렌즈일체형 플러거블 접속구조의 광도파로를 PDMS복제공정으로 제작된 mold를 이용하여 임프린트 공정을 통해 제작하였다. 따라서 본 논문에서는 수동정렬이 가능한 광PCB접속용 플러거블 렌즈 구조의 제작이 가능함을 확인하였다.

• 한국광학회지
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• 제16권1호
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• pp.79-84
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• 2005

정력 오차 허용 범위를 증가 시켜서 효과적인 수동정렬이 가능토록 하기 위한 단일 모드 대형 코어 폴리머 광도파로를 구현하였다. 대형 코어 광도파로는 TEC(thermally expanded core) 광섬유의 모드와 일치하는 큰 도파모드를 가진다. 이로 인해 광섬유와 도파로의 정렬오차로 인한 모드 결합 손실을 줄일 수 있게 된다. 코어와 클래딩의 굴절률 차이가 5 ${\times}$ $10^{-4}$ 인 폴리머 재료를 이용하여 25 ${\times}$ 25 $\mu\textrm{m}$$^2$ 크기의 정사각형 광도파로를 제작하였으며 도파모드 관측결과 단일모드로 동작함을 확인하였다. 이와 같이 두꺼운 형태의 광도파로 구조 제작을 위하여 자외선 경화를 이용한 인젝션 몰딩(injection molding) 공정을 사용하였다. 제작된 광도파로 소자를 TEC 광섬유와 정렬연결을 할 때 정렬오차가 4.5 $\mu\textrm{m}$ 까지 증가하더라도 삽입손실 증가는 0.5 dB 이하고 유지됨을 확인하였다.

• 한국정밀공학회지
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• 제23권2호
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• pp.57-64
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• 2006

Optical filters in WDM are passive communication components used in case of transmitting and reflecting lights with specific wavelengths. In this paper, a novel mechanism for the automatic and optical alignment has been presented. It includes minimum axes not to be coupled each other. The automatic spectrum inspection system has been developed to improve the alignment time of reference optical ray, spectrum inspection time and inspection quality, simultaneously. It has been confirmed that the proposed spectrum inspection system is faster, more precise and more reliable than those based on the conventional handwork.

• ETRI Journal
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• 제27권4호
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• pp.446-448
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• 2005

Using tightly focused femtosecond laser pulses, we produce an optical waveguide and devices in transparent materials. This technique has the potential to generate not only channel waveguides, but also three-dimensional optical devices. In this paper, an optical splitter and U-grooves, which are used for fiber alignment, are simultaneously fabricated in a fused silica glass using near-IR femtosecond laser pulses. The fiber- aligned optical splitter has a low insertion loss, less than 4 dB, including an intrinsic splitting loss of 3 dB and excess loss due to the passive alignment of a single-mode fiber. Finally, we present an output field pattern, demonstrating that the splitting ratio of the optical splitter becomes approximately 1:1.

• 마이크로전자및패키징학회지
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• 제19권4호
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• pp.13-18
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• 2012

By the need for high-speed data transmission in PCB, the studies on the optical PCB has been conducted with optical interconnection and its packaging technology. Particularly, the polymer-based optical interconnection has been extensively studied with the advantages such as cost-effective and ease of process. For high-efficiency and passive alignment, the studies were performed using the 45 degree mirrors, MT connector, and etc. In this work, integrated PLC device and fiber alignment array block was fabricated by using imprint technology to solve the alignment and array problem of optical device and the optical fiber. The fabricated integrated block for optical interconnection of PLC device has achieved higher precision of decreasing the dimensional error of the patterns by optimization of process and its insertion loss has an average value of 4.03dB, lower than criteria specified by international standard. In addition, a optical waveguide with built-in lens has been proposed for high-efficiency and passive alignment. By simulation, it was confirmed that the proposed structure has higher coupling efficiency than conventional no-lens structure and has the broad tolerance for the spatial offset of optical waveguide.

• 대한물리의학회지
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• 제15권3호
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• pp.51-59
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• 2020

PURPOSE: The purpose of this study was to provide clinical basic data to reduce pain and improve function by comparing neck muscle activity and neck alignment using self-stretching and passive stretching exercises for chronic neck pain caused by forward head posture. METHODS: The subjects were divided into 15 subjects assigned to perform self-stretching exercise and 15 subjects assigned to perform passive stretching exercise. The intervention was conducted for a total of 4 weeks. The muscle activity in the neck was measured by surface electromyography (EMG) before intervention, and craniovertebral and cranial rotation angles were measured by X-ray. The 4-week intervention was conducted and the above items re-measured in the same manner and analyzed. RESULTS: Muscle activity within both groups after intervention using self-stretching or passive stretching exercise was significantly different (p < .05)(p < .01). Neck alignment of both groups was significantly different (p < .001)(p < .01). Further, muscle activities of the upper trapezius and splenius capitis muscles showed significant differences (p<.05). Lastly, neck alignment showed statistically significant difference (p < .05). CONCLUSION: Self-stretching exercise activated motor nerves as a posture correction exercise, thereby improving inhibition of muscle activity, muscle contraction delay, and pathological conditions of the muscle. For future research, interventions of self-stretching exercise will be needed for patients with chronic back pain accompanied by forward head posture, and various clinical studies on postural improvement of forward head posture by maintaining a normal muscle tone state are needed.

• 한국통신학회논문지
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• 제31권11A호
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• pp.1053-1058
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• 2006

본 논문은 GE-PON 등 FTTH용 광액세스망 시스템에 사용되는 저가격 광모듈 제작을 위하여, 1.31/1.49um 양방향 구성의 하이브리드집적 PLC칩을 사용한 효율적인 광모듈 패키징 기술을 제안하였다. 수동 광섬유정렬기술과 nonhermetic 플라스틱 패키지 기술을 적용하여 광모듈을 제작하였으며, 광결합효율과 전기-광학적 특성을 측정하였다. 제작된 광모듈의 광결합효율은 광축정렬 허용오차 40um내에서 0.5dB이하의 광결합손실을 나타내었고, -24dBm 이하의 수신감도와 광출력 1.5mW이상, 소광비 10dB이상, tracking error 0.3dB이하의 온도특성이 GE-PON ONU용 광모듈 규격을 만족함을 확인하였다.

• 마이크로전자및패키징학회지
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• 제14권3호
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• pp.7-13
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• 2007

광통신용 광모듈에서 광소자와 광섬유 또는 도파로를 정밀하게 정렬 및 접합하기 위하여 플립칩본딩 방법 이 널리 이용되고 있다. 이때 광소자를 정확한 위치에 정렬시키기 위하여 기판과 광소자 양쪽에 정렬용 마크를 제작하고 플립칩본더 등을 사용하여 정렬마크를 관찰하며 광소자를 정렬 및 본딩하게 된다. 본 연구에서는 이러한 정렬마크의 제작비용을 줄이고 광섬유와 수광소자(PD 칩)의 수동정렬을 용이하게 하기 위하여 He-Ne 레이저(파장 633nm)인 가시광을 이용한 정렬 및 플립칩본딩 방법을 연구하였다. 광섬유에서 방출되는 레이저 광을 육안으로 관찰하면서 수광소자를 정렬하므로써 패키징에 소요되는 시간과 경비를 절감하고 광모듈의 저가격화를 실현 할 수 있는 새로운 방법이다. 광섬유에 가공되어 있는 V-노치를 경유하여 가시광이 광섬유에 대해 직각방향으로 방출되고 이것을 수광소자와 정렬하는 방법이다. 본 연구결과 광정렬을 위해 입사된 633 nm파장의 가시광 레이저와 통신용 레이저인 1550 nm 파장사이의 파장 차이에 의한 광경로 차이는 약 4m으로 무시가능하고 최대 광세기 지점에서 ${\pm}20\;{\mu}m$ 범위내에서는 광결합효율 변화는 약 2%이었으며 최대 광결합효율은 약 23.3%이었다.

• 한국광학회:학술대회논문집
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• 한국광학회 2003년도 제14회 정기총회 및 03년 동계학술발표회
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• pp.298-299
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• 2003

As the demand for high frequency(bandwidth) optical module of reduced cost is increased, there are considerable needs for low cost／ high reliable optical packaging method. In order to meet these requirements, the researches using silicon optical bench(SiOB) technology have been developed as one of the leading technology. In this paper, we discuss optical package using one aspherical lens mounted on SiOB by passive alignment, and present the reliability data for the optical module, which are temperature cycling between 40C and +85C, and high temperature storage 85C(unbiased), 2000hour.

• 대한물리의학회지
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• 제10권2호
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• pp.17-27
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• 2015

PURPOSE: The purpose of this study was to compare the effects of three interventions (intervention by passive range of motion exercise plus manual cervical traction, Mulligan's joint mobilization, and strengthening exercises) after Kaltenborn's joint mobilization on the cervical spine alignment, and muscle activity in patients with a forward head posture. METHODS: The subjects were 39 students from H University in Chungnam and C University in Jeonbuk. The subjects in each group attended training sessions three times a week for four weeks. We used one-way ANOVA and Scheffe's post hoc test to compare values between groups, and used paired t-test to compare the values of the dependent variables within groups. RESULTS: The results showed that the active intervention group experienced a significant increase compared to the passive intervention group in terms of the craniovertebral angle, cervical lordosis angle, and had significant decreases compared to the passive intervention group in terms of the upper trapezius muscle activity. The active intervention group also had significant increases in craniovertebral angle and decreased anterior scalene muscle activity than the active-assistive intervention group. The active-assistive intervention group had significant decreases compared to the active intervention group in terms of the serratus anterior, levator scapulae, and splenius capitis muscle activity. CONCLUSION: It appears that the subjects with a forward head posture had significant improvements in the cervical lordosis angle, cranial rotation angle, craniovertebral angle, and muscle activity after intervention by Mulligan's joint mobilization (active-assistive intervention component) and strengthening exercises (active intervention component) after applying Kaltenborn's joint mobilization.