| 主权项 |
1. A measurement apparatus for measuring a terahertz wave by using time-domain spectroscopy, comprising:
a terahertz wave generating unit configured to generate the terahertz wave in response to incidence of pump light thereon; a terahertz wave detecting unit configured to detect the terahertz wave in response to incidence of probe light thereon; an adjusting unit configured to adjust an optical path length difference, which is a difference between an optical path length of the pump light and an optical path length of the probe light, and adjust a timing at which the terahertz wave and the probe light reach the terahertz wave detecting unit; an amount-of-change detecting unit configured to detect an amount of change in the optical path length difference; a vibration obtaining unit configured to obtain information about a magnitude of vibration of the adjusting unit by using a detection result generated by the amount-of-change detecting unit in a state where the adjusting unit is stationary; a determining unit configured to determine, by using the information, whether the magnitude of the vibration of the adjusting unit is within a range of an allowable value; and an output unit configured to output a measurement start trigger in a case where the determining unit determines that the magnitude of the vibration of the adjusting unit is within the range of the allowable value. |
