| 摘要 |
PURPOSE:To eliminate the necessity for making a semiconductor crystal thin and to perform measurement without moving a semiconductor, by splitting a light pulse to be measured into two pulses to give relative light path length difference before synthesizing both pulses to one luminous flux and allowing said luminous flux to be incident to the semiconductor crystal. CONSTITUTION:A light pulse to be measured is split into two pulses by a half mirror 1 while two pulses are reflected by prisms 6, 7 to be again synthesized to one luminous flux which is, in turn, incident to a semiconductor crystal 4 through a lens 8. The electric conductivity change due to two-photon absorption of the crystal 4 is measured by a circuit consisting of a DC power supply 9, a differential amplifier 10 and a load resistor 19 to be recorded on a recorder 5. The prism 7 is reciprocally moved by a moving stand 20 and the relative light path length difference of the split luminous fluxes is changed to perform measurement. The conductivity change of the crystal 4 is proportional to the square of he electric field intensity of light. The continuous time (pulse width) of the light pulse to be measured is calculated from the electric field intensity change of incident light due to light path length difference and the delay time due to said difference. Since only one surface of the crystal 4 is used in measurement, it is unnecessary to make the crystal thin. |
