TY - GEN
T1 - Computer-controlled optical fiber sensor system for the characterization of ultrasound
AU - Wong, Wai Keung
AU - Chiang, Kin Seng
AU - Dong, X. P.
AU - Chan, H. P.
PY - 1996
Y1 - 1996
N2 - A computer-controlled optical fiber sensor system has been developed for the characterization of ultrasonic transducers in the megahertz range. The sensing element used is a short length of highly birefringent optical fiber. When an ultrasonic wave is incident normally upon the fiber, the birefringence, or the phase difference between the two polarized light waves in the fiber, is modulated. The phase modulation is converted into an intensity-modulated signal by means of polarimetry. To optimize and stabilize the signal against environmental effects such as temperature variations, a liquid-crystal phase retarder, controlled by feedback electronics, is placed in the optical path. Intensity noises arising from the laser source and the fiber leads are also eliminated by using signal processing techniques. The spatial intensity profile of an ultrasonic beam can be determined by scanning the sensing fiber across the ultrasonic beam. Fiber scanning and data acquisition are controlled by a personal computer. In this paper, the principle and the implementation of the sensor system are described. Experimental results obtained from characterizing commercial ultrasonic transducers are presented.
AB - A computer-controlled optical fiber sensor system has been developed for the characterization of ultrasonic transducers in the megahertz range. The sensing element used is a short length of highly birefringent optical fiber. When an ultrasonic wave is incident normally upon the fiber, the birefringence, or the phase difference between the two polarized light waves in the fiber, is modulated. The phase modulation is converted into an intensity-modulated signal by means of polarimetry. To optimize and stabilize the signal against environmental effects such as temperature variations, a liquid-crystal phase retarder, controlled by feedback electronics, is placed in the optical path. Intensity noises arising from the laser source and the fiber leads are also eliminated by using signal processing techniques. The spatial intensity profile of an ultrasonic beam can be determined by scanning the sensing fiber across the ultrasonic beam. Fiber scanning and data acquisition are controlled by a personal computer. In this paper, the principle and the implementation of the sensor system are described. Experimental results obtained from characterizing commercial ultrasonic transducers are presented.
UR - https://www.scopus.com/pages/publications/0030403247
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-0030403247&origin=recordpage
M3 - RGC 32 - Refereed conference paper (with host publication)
SN - 0819422967
SN - 9780819422965
VL - 2895
SP - 576
EP - 580
BT - Proceedings of SPIE - The International Society for Optical Engineering
T2 - Fiber Optic Sensors V
Y2 - 6 November 1996 through 7 November 1996
ER -