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광섬유 Sagnac 간섭계를 이용한 초음파의 비접촉식 감지

Non-contact Detection of Ultrasonic Waves Using Fiber Optic Sagnac Interferometer

  • 이정주 (한국과학기술원 기계공학과) ;
  • 장태성 (한국과학기술원 기계공학과) ;
  • 이승석 (한국표준과학연구원 비파괴계측그룹) ;
  • 김영길 (한국표준과학연구원 비파괴계측그룹) ;
  • 권일범 (한국표준과학연구원 비파괴계측그룹) ;
  • 이왕주
  • Lee, Jeong-Ju (Dept. of Mechanical Engineering, Korea Advanced Institute of Science and Technology) ;
  • Jang, Tae-Seong (Dept. of Mechanical Engineering, Korea Advanced Institute of Science and Technology) ;
  • Lee, Seung-Seok (Measurement Group, Korea Reserch Institute of Standards and Science) ;
  • Kim, Yeong-Gil (Measurement Group, Korea Reserch Institute of Standards and Science) ;
  • Gwon, Il-Beom (Measurement Group, Korea Reserch Institute of Standards and Science) ;
  • Lee, Wang-Ju
  • 발행 : 2001.09.01

초록

This paper describes a fiber optic sensor suitable for non-contact detection of ultrasonic waves. This sensor is based on a fiber optic Sagnac interferometer. Quadrature phase bias between two interfering laser beams in Sagnac loop is introduced by a polarization controller. A stable quadrature phase bias can be confirmed by observing the interferometer output versus phase bias. This method eliminates a digital signal processing for detection of ultrasonic waves using Sagnac interferometer. Interference intensity is affected by the frequency of ultrasonic waves and the time delay of Sagnac loop. Collimator is attached to the end of the probing fiber to focus the light beam onto the specimen surface and to collect the reflected light back into the fiber probe. Ultrasonic waves produced by conventional ultrasonic transducers are detected. This fiber optic sensor based on Sagnac interferometer is very effective for detection of small displacement with high frequency such as ultrasonic waves used in conventional non-destructive testing.

키워드

참고문헌

  1. Scruby, C.B. and Drain, L.E., 1990, Laser Ultrasonics: Techniques and Applications, Adam Hilger, New York
  2. Rastogi, P.K. and Inaudi, D., 2000, Trends in Optical Nondestructive Testing and Inspection, Elsevier, Oxford
  3. Cho, H., Ogawa, S. and Takemoto, M., 1996, 'Non-contact Laser Ultrasonics for Detecting Subsurface Lateral Defects,' NOT & E International, Vol. 29, No. 5, pp. 301-306 https://doi.org/10.1016/S0963-8695(96)00033-3
  4. Fomitchov, P., Steckenrider, J.S., Krishnaswamy, S. and Achenbach, J.D., 1997, 'Frequency- shifted Low-noise Sagnac Sensor for Ultrasonic Measurements,' Review of Progress in Quantitative Nondestructive Evaluation, Vol. 16, Edited by D.O. Thompson and D.E. Chimenti, Plenum Press, New York, pp. 2053-2060
  5. Mitra, B., Shelamoff, A. and Booth, D.J., 1998, 'An Optical Fibre Interferometer for Remote Detection of Laser Generated Ultrasonics,' Measurement Science & Technologies, Vol. 9, pp. 1432-1436 https://doi.org/10.1088/0957-0233/9/9/009
  6. Fomitchov, P., Krishnaswamy, S. and Achenbach, J.D., 1998, 'Sagnac Interferometer for Ultrasound Detection on Rough Surfaces,' Nondestructive Characterization of Material VIII, Edited by Robert E. Green Jr., Plenum Press, New York, pp. 97-103
  7. 김경조, 山脇 壽, 장경영, 2000, '마이켈슨 간섭계를 이용한 레이저 여기 초음파의 검출,' 비파괴검사학회지 , Vol. 20, No. I, pp. 27-32
  8. Fomitchov, P., Kromine, A.K., Krishnaswamy, S. and Achenbach, J.D., 2000, 'Sagnac-type Fiber-optic Array Sensor for Detection of Bulk Ultrasonic Waves,' IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, Vol. 47, No. 3, pp. 584-590 https://doi.org/10.1109/58.842045
  9. Udd, E., 1990, Fiber Optic Sensors, John Wiley & Sons, Inc., New York
  10. 권일범, 강현규, 김천곤, 홍창선, 1998, '3 x 3 수동변조 되풀이 광섬유 마이켈슨 간섭센서에 의한 구조물의 변형률 측정,' 대한기계학회논문집 A권, 제22권 제1호, pp. 80-89
  11. 이상열, 정재강, 1998, '표면부착 광섬유센서를 사용한 변형률-온도의 동시측정,' 대한기계학회논문집 A권, 제22권 제5호, pp. 895-901
  12. 김정석, 윤형규, 설재수, 1999, '실험을 통한 소형 고감도 광섬유 하이드로폰의 감지성능 연구,' 한국소음진동공학회지, 제9권 제6호, pp. 1152-1156
  13. 류치영, 구본용, 홍창선, 2000, '스마트 구조물의 변형률 모니터링을 위한 광섬유 브래그 격자 센서 시스템 개발에 관한 연구,' 한국항공우주학회지, 제28권 제4호, pp. 58-66
  14. Gottwald, E. and Pietzsch, J., 1988, 'Measurement Method for Determination of Optical Phase Shifts in 3x 3 Fiber Couplers,' Electronics Letters, Vol. 24, No. 5, pp. 265-266
  15. Dandridge, A., Wang, C.C., Tveten, A.B. and Yurek, A.M., 1994, 'Performance of 3x 3 Couplers in Fiber Optic Sensor Systems,' Proceedings of SPJE - the International Society for Optical Engineering, Vol. 2360, pp. 549-552 https://doi.org/10.1117/12.184986
  16. 남성현, 2000, 'Sagnac 간섭계률 이용한 광섬유 음향 센서의 동적 범위 향상 기법,' 센서학회지, 제9권 제6호, pp. 416-423
  17. 이왕주, 1999, 편광 의존성을 없앤 이중 주파수 헤테로다인 간섭계형 광섬유 센서어레이에 대한 연구, 한국과학기술원 박사학위논문
  18. 한기호, 이왕주, 김병윤, 1998, '광섬유 Sagnac 간섭계 수중음향센서어레이의 특성 조사 및 신호처리,' Proceedings of Photonics Conference '98, pp. 119-120
  19. Moss, B.C. and Scruby, C.B., 1988, 'Investigation of Ultrasonic Transducers Using Optical Techniques,' Ultrasonics, Vol. 26, No. 4, pp. 179-188 https://doi.org/10.1016/0041-624X(88)90065-0