| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve the problems wherein, in the case where an optical path length is not scanned at equal speed, accuracy is lowered and a long measuring time is required, because interpolation processing of measured data is necessary in a conventional rapid scan system. <P>SOLUTION: A laser interferometer 8 is attached to an optical path length scanning part 6 for changing the optical path length of an optical path from a laser light source 1 to a transmission part (terahertz light source) 9, and a pulse signal 15 is generated at each fixed displacement interval, and a polarity signal 16 showing the moving direction is generated. Both signals 15, 16 are delayed by delay parts 17, 18 as much as a time delay portion in an analog electric circuit, to thereby allow each timing to agree with each other. A sample/hold circuit 20 samples a detection signal of a reception part 12 synchronously with a pulse signal 15', and it is converted into a digital value by an A/D conversion part 21, hereby, measured data at every fixed displacement intervalΔL can be acquired accurately. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
