서지주요정보
반도체 광증폭기를 이용한 모드 록킹된 광섬유 레이저와 자이로스코프에의 응용 = Mode locked fiber laser using a semiconductor laser amplifier and its application to the gyroscope
서명 / 저자 반도체 광증폭기를 이용한 모드 록킹된 광섬유 레이저와 자이로스코프에의 응용 = Mode locked fiber laser using a semiconductor laser amplifier and its application to the gyroscope / 박경현.
저자명 박경현 ; Park, Kyung-Hyun
발행사항 [대전 : 한국과학기술원, 1996].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8006619

소장위치/청구기호

학술문화관(문화관) 보존서고

DPH 96001

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

This thesis describes fabrication and transmission experiments of the distributed feedback(DFB) laser diode(LD) module that is applied to the performance improvement of the mode-locked fiber laser gyroscope(MLFLG) using DFB-LD as gain medium. The DFB laser module with stable single mode operation was developed for a 2.5Gbps optical transmission systems. DFB lasers with various active layer structures including Bulk, multiple quantum well(MQW), and strained-MQW in planar buried heterostructure(PBH) were fabricated by three step crystal growth and two step mesa etching. Typical characteristics of the fabricated DFB-LD shows side mode suppression ratio(SMSR) of more than 35dB and the threshold current of 11.5mA. The key parameters of DFB-LD such as linewidth enhancement factor, chirping, and differential gain were also investigated and compared for various active layers. Single mode fiber pigtailed DFB laser module was designed and fabricated. A single planar-convex GRIN lens was adopted for the simple construction of optical coupling system, and laser welding was used for assembling the submodule assemble for an accurate alignment of optical elements. The fabricated laser module shows 40% coupling efficiency and modulation bandwidth of 2.6 GHz. The optical transmission performances of the fabricated laser module were evaluated by a bit error rate(BER) measurement system. Received power of -33dBm was obtained after transmitting 47 km in a conventional optical fiber, and dispersion penalty was 0.7dB. The second part of the thesis deals with a recently demonstrated MLFLG with a new form of an output in time domain. The output of the MLFLG is a series of mode-locked optical pulses, with two pulses per every round-trip time of light in the laser cavity. The separation of the two sets of optical pulses in time domain varies as a function of rotation rate. However, the MLFLG built with a fiber amplifier exhibits very strong gain competition between the two sets of mode-locked optical pulses, leading to detrimental errors in the measurements of rotation rate. In this thesis, a solution to the above stated problem is presented by using a semiconductor laser amplifier(SLA) with a fast gain recovery for the gain medium of the MLFLG. The SLA used in the MLFLG was DFB-LD fabricated during this work and it proved itself as suitable gain medium and detector of optical pulses. Experimental results show an almost complete suppression of the gain competition resulting in the much improved operation of the MLFLG with stable optical pulses. An additional simplification of the optical circuit is also realized by using the SLA as a photodetector while providing the required gain for the MLFLG. With the stability of the pulses, we could analyze, for the first time, the performance of the MLFLG in rotation rate measurements. The shift of the timing of the mode-locked optical pulses as a function of rotation rate measured by a time interval analyzer (HP 5371A) agreed well with theoretical expectation. The mean time deviation of the time interval between each set of mode-locked pulses were also evaluated by a universal counter/timer (Tek DC5010) when the gyroscope is at rest. The rms time jitter was 11.08 ps around the mean value of 390 ps for integration time of 2.66 sec. The rms time jitter corresponds to about 40.6 mrad of optical phase error and 14.6 deg/h of rotation rate error. Considering the integration time of 2.66 seconds, the random walk noise is calculated to be 0.4 deg/√h. The offset of 390 ps from the half period of the applied modulation signal corresponds to 1.43 mrad of optical phase offset and about 515 deg/h of rotation rate offset.

서지기타정보

서지기타정보
청구기호 {DPH 96001
형태사항 iii, 147 p. : 삽도 ; 26 cm
언어 한국어
일반주기 부록 수록
저자명의 영문표기 : Kyung-Hyun Park
지도교수의 한글표기 : 김병윤
지도교수의 영문표기 : Byoung-Yoon Kim
학위논문 학위논문(박사) - 한국과학기술원 : 물리학과,
서지주기 참고문헌 : p. 142-147
주제 레이저 다이오드
분포궤환형 레이저 다이오드
자이로스코프
모드 록킹
광섬유 레이저
Laser Diode
DFB-LD
Gyroscope
Mode-Locking
Fiber Laser
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