서지주요정보
단일모드 광섬유를 이용한 모드록킹된 광섬유 레이저 자이로스코프에 관한 연구 = Mode-locked fiber laser gyroscope using single-mode fiber
서명 / 저자 단일모드 광섬유를 이용한 모드록킹된 광섬유 레이저 자이로스코프에 관한 연구 = Mode-locked fiber laser gyroscope using single-mode fiber / 여영배.
저자명 여영배 ; Yeo, Yeong-Bae
발행사항 [대전 : 한국과학기술원, 2003].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8014238

소장위치/청구기호

학술문화관(문화관) 보존서고

DPH 03004

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

Mode-locked fiber laser gyroscope (ML-FLaG) is a fiber laser employing a Sagnac interferometer both as a rotation sensing element and a feedback reflector in a laser cavity. It consists of a laser cavity formed by a conventional mirror and a Sagnac interferometer, a gain medium, and a phase modulator inside the Sagnac loop. The output of the ML-FLaG is an optical pulse train having two pulses per every round-trip time of light in the laser cavity. The time interval between the two consecutive pulses is a function of rotation rate, which can be measured by using a time interval counter or a lock-in amplifier. The time interval detection has advantages of independence from the total power and simplicity of signal processing. But it has strong dependence on the peak power difference between mode-locked pulses. On the other hand, the lock-in detection has merits of linear proportionality to the rotation rate and immunity from the peak power difference. However, this method also has a disadvantage of strong dependence on the total power. The ML-FLaG with an erbium-doped fiber (EDF) as a gain medium has been constructed and the output characteristics of the ML-FLaG has been investigated. The ML-FLaG built with an EDF exhibited very strong gain competition between two mode-locked pulses when modulation frequency was tuned exactly to the resonant frequency of the laser cavity. However, we could achieve stable mode-locking, when the modulation frequency was slightly detuned from the resonant frequency, where the pulse-duration (a few tens of nsec) and spectral width (a few nm) was fairly large. The ML-FLaGs based on a polarization-maintaining fiber (PMF:ML-FLaG) and a conventional single-mode fiber (SMF:ML-FLaG) were composed separately and characterized using both a time interval counter and a lock-in amplifier. The long term drift and the short term noise of PMF:ML-FlaG were 500 μrad and 18 μrad/$\sqrt{Hz}$ with time interval detection. They were 13 μrad and 6.8 μrad/$\sqrt{Hz}$ with lock-in detection. Significant improvements by the lock-in detection method, means that fairy large peak power difference existed in the case of PMF:ML-FlaG. It was proved that the peak power difference came from the loss modulation in the LiNbO3 integrated-optic gyrochip. The optimum configuration of SMF:ML-FLaG was found out, by which nonreciprocal pulses could not build up, no signal fading took place, and polarization modulation was suppressed. The long term drift and the short term noise of SMF:ML-FlaG were 52 μrad and 18 μrad/$\sqrt{Hz}$ , with time interval detection. Even though SMF:ML-FLaG consisted of cheap components, its performance was comparable to that of PMF:ML-FlaG, which composed of expensive components.

서지기타정보

서지기타정보
청구기호 {DPH 03004
형태사항 iv, 89 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Yeong-Bae Yeo
지도교수의 한글표기 : 김병윤
지도교수의 영문표기 : Byoung-Yoon Kim
학위논문 학위논문(박사) - 한국과학기술원 : 물리학과,
서지주기 참고문헌 : p. 87-89
주제 광섬유 레이저
광섬유 센서
레이저 센서
자이로스코프
모드록킹
Fiber Laser
Fiber Sensor
Laser Sensor
Gyroscope
Mode-Locking
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