• 한국항해항만학회지
• /
• 제32권9호
• /
• pp.723-727
• /
• 2008

Sensing performances of evanescent field absorption (EFA) hetero-core fiber sensor has been presented based on EFA by changing the length and the core diameter of the single mode fiber. Experimental results have demonstrated a good feature in their relationship between the length and the core diameter of the single mode fiber. The sensor consists of 2 fiber optics which have the same cladding diameter of $125{\mu}m$ However one fiber optic used is single mode and has varying core diameter ranging from 3.3 to $5.6{\mu}m$. The other fiber is multimode type and has a thicker fixed core diameter of $62.5{\mu}m$. The 2 fiber optics are thermally spliced together. Experiments conducted to measure the resonance wavelength were carried out over a range of refractive index, to find the optimum sensing length Experiments show that core diameter of the single mode fiber and sensing length offects the linearity and sensitivity.

• 정보와 통신
• /
• 제3권1호
• /
• pp.52-63
• /
• 1986

본 고는 통신망 발전 전략, 광 통신의 세계적인 추세, KTA 가입자망에서의 fiber hubbing망, 새로운 디지털 서어비스를 위한 가입자망 전략-DLC(Digital Loop Carrier), CSA(Carrier Serving Area)의 개념과 광전송기술을 이용하여 기존 가입자망에 중첩하는 overlay 방식 및 그것의 ISDN적용을 논의한다

• 한국광학회지
• /
• 제16권6호
• /
• pp.490-493
• /
• 2005

본 논문은 광자 결정 광섬유에서 100 fs의 펄스 폭을 갖는 펌프 광원의 파장과 입력파워에 따른 초 광대역 광원 생성에 대해 실험적으로 연구하였다. 적절한 파라미터들을 조절함으로써 광 스펙트럼 진폭의 균일함이 10 dB 이내에서 약 750 nm의 스펙트럼 폭을 갖는 초 광대역 광원을 얻어냈다. 사용한 광자 결정 광섬유의 길이는 2 m였고, 펌프광원으로는 모드 록킹된 Ti:Sapphire laser를 사용하였다. 또한, 펌프 광원의 여러 가지 변수들을 바꿔줌으로써 초 광대역 광원의 다양한 스펙트럼 현상을 조절할 수 있었다.

• 한국광학회지
• /
• 제16권1호
• /
• pp.99-102
• /
• 2005

광섬유 링 레이저의 출력파장 가변을 위해서 신뢰성있는 새로운 스트레인 인가장치를 제작하고 이 장치를 이용하여 파장가변 광섬유 링 레이저를 구현하였다. 제작된 광섬유 링 레이저의 출력파워는 -12 dBm이었으며, 선폭은 0.05 nm이었다. 새로운 스트레인 인가장치를 이용하여 광섬유에 8000 $\mu$ strain을 인가하였을 때 광섬유 링 레이저의 출력파장은 약 10 nm 가변되는 것을 확인 할 수 있었다.

• 한국광학회지
• /
• 제24권1호
• /
• pp.17-22
• /
• 2013

High performance plastic optical fiber (POF) $N{\times}N$ star couplers are implemented based on fusing and combining technology. A set of cladding-removed POFs are fused into a solid body by heating and pressing them together to form the transition region between the input and output sides. The operation principle of the proposed star coupler is explained based on ray optics. To demonstrate the performance of the device, $2{\times}2$, $4{\times}4$ and $6{\times}6$ type POF couplers were fabricated and characterized. Performances of the POF star couplers were evaluated in terms of the flatness of the coupling ratios and excess losses.

• Current Optics and Photonics
• /
• 제5권2호
• /
• pp.121-128
• /
• 2021

We propose a novel, tiny optical receiver engine utilizing an all-in-one package based on embedded optics technology. The package's best transmission S21 and reflection S22 opto-electric (OE) bandwidths are 49.8 GHz and 34.9 GHz, respectively, and the reflectance of the optical engine is below -31.7 dB for all channels. The engine satisfies the MIL-STD-883G standard for reliability tests, such as mechanical and thermal shock, and vibration resistance. The sensitivity after 10 km single-mode fiber (SMF) transmission is below -8 dBm. The optical receiver engine is cost-competitive and applicable for 400G coarse wavelength division multiplexing 4 (CWDM4) 10 km optical transceivers.

• 한국광학회지
• /
• 제29권5호
• /
• pp.187-203
• /
• 2018

본 논문에서는 지난 40여 년간 이룩된 광통신 기술의 눈부신 발전 과정을 되돌아보고 예상되는 향후 발전 방향에 대하여 기술하였다. 특히, 초고속 대용량 광전송 시스템의 발전 과정에서 핵심적인 역할을 수행한 기술들을 역사적 관점에서 정리하였다. 본 논문은 광통신 분야에 새로이 입문하는 젊은 공학도들을 위하여 작성된 것이다.

• 한국정보전자통신기술학회논문지
• /
• 제6권4호
• /
• pp.272-277
• /
• 2013

In this paper the effect of instability and chaos in optical fiber networks based on the Internet is described. Nonlinear optical fiber effect especially Brillouin scattering in networks has emerged as the essential means for the construction of active optical devices used for all-optic in-line switching, channel selection, amplification, oscillation in optical communications and a host of other applications. The inherent optical feedback by the back-scattered Stokes wave in optical networks also leads to instabilities in the form of optical chaos. This paradigm of optical chaos in fiber Internet serves as a test for fundamental study of chaos and its suppression and exploitation in practical application in optical fiber communication. This paper attempts to present a survey and some of our research findings on the nature of Brillouin chaotic effect on Internet based optical communication.

• 한국정보전자통신기술학회논문지
• /
• 제1권1호
• /
• pp.61-66
• /
• 2008

In this paper the effect of instability and chaos in optical fiber networks based on the Internet is described. Nonlinear optical fiber effect especially Brillouin scattering in networks has emerged as the essential means for the construction of active optical devices used for all-optic in-line switching, channel selection, amplification, oscillation in optical communications and a host of other applications. The inherent optical feedback by the back-scattered Stokes wave in optical networks also leads to instabilities in the form of optical chaos. This paradigm of optical chaos in fiber Internet serves as a test for fundamental study of chaos and its suppression and exploitation in practical application in optical fiber communication. This paper attempts to present a survey and some of our research findings on the nature of Brillouin chaotic effect on Internet based optical communication.

• Current Optics and Photonics
• /
• 제1권4호
• /
• pp.308-314
• /
• 2017

A particular optical receiver has its own optical receiver modes (ORMs) determined by its optical and electrical filters. Superposing the ORM waveforms at the transmitter, we can generate a new type of optical signals, called ORM signals. After optical detection, they produce pre-specified voltage waveforms accurately, which is advantageous for digital signal processing. Assuming a Gaussian optical receiver, where the optical and electrical filters are Gaussian, we illustrate various phase-shift keying ORM signals using two ORMs by changing their relative phase. We also illustrate multi-level ORM signal patterns using two or more ORMs.