서지주요정보
어븀 첨가 광섬유 고리형 레이저의 출력 및 종모우드 맥놀이 신호 특성 조사 = Output power and longitudinal mode beat frequency characteristics of Er-doped fiber ring laser
서명 / 저자 어븀 첨가 광섬유 고리형 레이저의 출력 및 종모우드 맥놀이 신호 특성 조사 = Output power and longitudinal mode beat frequency characteristics of Er-doped fiber ring laser / 이희열.
저자명 이희열 ; Lee, Hee-Yeal
발행사항 [대전 : 한국과학기술원, 1995].
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소장정보

등록번호

8005113

소장위치/청구기호

학술문화관(문화관) 보존서고

MPH 95026

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

An Er-doped fiber ring laser was characterized in order to examine the main causes that affects the linewidth of longitudinal mode beat(LMB) frequency. The frequency linewidth of LMB determines the resolution of the sensors using LMB signal. For example, the possibility of rotation rate sensing in Er-doped fiber ring laser was demonstrated recently, which used the LMB signal between clockwise(CW) and counterclockwise(CCW) laser outputs. The ring laser was constructed with 5m long, 500 ppm Er-doped fiber and a length of single mode fiber at the 1.55 ㎛ wavelength and polished type tunable directional couplers. It was pumped with an $Ar^+$ laser at the 514.5 nm wavelength and its lasing center wavelength was 1.53 ㎛. The ring laser oscillated in both CW and CCW direction with a stable output power. As the output coupling ratio varied from 0.05 to 0.8, its threshold pump power varied from 70 mW to 160 mW, and slope efficiency ranged from 5.5 × $10^{-5}$ to 1.44 × $10^{-3}$ for CW laser and from 1.5 × $10^{-4}$ to 6.89 × $10^{-3}$ for CCW laser, which was due to the location of the output coupler relative to the gain medium and the loss elements inside the cavity. The optical spectra and the rf beat spectra of both CW and CCW laser were the same. Since the laser operated in multiple longitudinal modes, the LMB signal contains many beat components of laser longitudinal modes within it. The frequency linewidth of LMB was about $10^{-3}$ times that of longitudinal mode spacing and showed a tendency that it increased as the pump power increased or the output coupling ratio increased. As the cavity length was increased the frequency linewidth of LMB decreased but the ratio of the frequency linewidth of LMB signal to the mode spacing increased. For the possible origin of the frequency linewidth of LMB and its behavior, nonlinear mode pulling effect and the effect of the dispersion of both Er-doped and undoped fiber were considered. But the magnitude of these effects were $10^{-4}$ and $10^{-3}$ times smaller than that of the experimental results, respectively. The dominant cause of the broadening of the frequency linewidth of LMB signal has yet to be discovered.

서지기타정보

서지기타정보
청구기호 {MPH 95026
형태사항 iii, 58 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Hee-Yeal Lee
지도교수의 한글표기 : 김병윤
지도교수의 영문표기 : Byoung-Yoon Kim
학위논문 학위논문(석사) - 한국과학기술원 : 물리학과,
서지주기 참고문헌 : p. 55-58
주제 Optical fibers.
Beats (Acoustics)
Erbium.
링 레이저. --과학기술용어시소러스
광학 섬유. --과학기술용어시소러스
에르. --과학기술용어시소러스
맥놀이 (진동) --과학기술용어시소러스
Lasers.
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