| 摘要 |
PURPOSE:To obtain a thermal distribution information of a specific depth of a sample which depends on the number of irradiation light waves by taking out a frequency component within a specified range of a signal which is sampled and then applying a specified signal to it or performing its Fourier transformation. CONSTITUTION:When a modulation frequency f of each time resolution signal of a rapid scan interferometer 2 is only within a specified range, namely within a range which is smaller than half the repetition frequency of a pulse light source 1, a low-frequency component of that signal at a specified range is taken out by a low-pass filter 10, is amplified by a main amplifier 11, is sampled by a reference signal with a period which the interferometer 2 has by an AD converter 12, and is subjected to Fourier transformation by a computer 13, thus obtaining a pulse response function A of a light acoustic spectral method PAS indicating a thermal distribution information in depth direction for a light with the number of waves of a sample 4. On the other hand, when a frequency is outside a specified range, a signal where a component at a specified range is taken out is sampled and then phase compensation and conversion of the number of waves are performed by the computer 13, thus obtaining the PAS function A. |
