| 摘要 |
<p>PURPOSE:To improve sensitivity of a detection and to contrive reduction of a measuring time by changing the phase of pulsed light with the change of refraction index due to a Pockels effect and detecting the change of phase from an interference with a pulse light separately prepared. CONSTITUTION:The output light from a laser 1 is branched to two beams 2, 3 by a beam splitter 13. A sample is irradiated with the beam 2 through a delaying device 4 and an electrical signal generated thereby is propagated to an electrical engineering crystal 8. On the other hand, the beam 3 is branched further to beams 5, 6 by a beam splitter 14 and they are superposed by a half mirror 17 passing through the crystals 8, 9 repectively with mirrors 15 and lenses 16. The interference fringes are detected by a photodiode 10, and a voltage is impressed on the crystal 9 by a feedback circuit 11 so that the intensity becomes constant, then the voltage is read by a voltmeter 12. The voltage impressed in such a manner is equal to the electrical signal voltage objective to be measured. By this procedure, the voltage at the time point sampled with the pulsed light can be measured. After that, the time waveform is observed by delaying the pulsed light.</p> |
