Comments on "Fiber optic ultrasonic sensor using Raman-Nath light diffraction" [with reply]

In the title paper (ibid., vol.41, p.166-71 (1994), Wu, Shankar, Lewin, and Koller have described a novel fiber optic ultrasonic sensor using the principle of Raman-Nath light diffraction. Kwiek et al. comment on the paper for two reasons. 1) the theoretical model used, and 2) calibration and spatial resolution based on the interpretation of the quoted experimental results. In reply, Wu et al. assert that their theory is indeed valid and can explain the results obtained within the limits of experimental errors.<>