Terahertz wave spectroscopic measurement apparatus and terahertz wave spectroscopic measurement method

A terahertz wave spectroscopic measurement apparatus comprising:

• a pump light source configured to output pulsed light as pump light;
• a terahertz wave detection element configured to input a terahertz wave generated when a sample is processed by irradiating the sample with the pump light, input probe light over an input period of the terahertz wave, and output the probe light with polarization modulation according to an electric field of the terahertz wave;
• a quarter wave plate configured to change a polarization state of the probe light output from the terahertz wave detection element;
• a polarizing beam splitter configured to split the probe light output from the quarter wave plate into a first polarized light component and a second polarized light component orthogonal to each other;
• a streak camera configured to detect temporal waveforms of respective intensities of the first polarized light component and the second polarized light component of the probe light output from the polarizing beam splitter and of the pump light;
• and
• an analysis unit configured to perform spectroscopic measurement of the sample based on, out of the temporal waveform of the intensity of each of the first polarized light component and the second polarized light component of the probe light detected by the streak camera, a temporal waveform in a period including a time at which the pump light is detected by the streak camera, and monitor a processing status of the sample.

A terahertz wave spectroscopic measurement method comprising:

• a terahertz wave generation step of inputting pulsed light output as pump light from a pump light source to a terahertz wave generation element, and generating a terahertz wave by the terahertz wave generation element;
• a modulation step of inputting the terahertz wave passed through a sample to a terahertz wave detection element, inputting probe light to the terahertz wave detection element over an input period of the terahertz wave, and outputting the probe light with polarization modulation according to an electric field of the terahertz wave by the terahertz wave detection element;
• a polarized light splitting step of splitting, by a polarizing beam splitter, the probe light output from the terahertz wave detection element and passed through a quarter wave plate into a first polarized light component and a second polarized light component orthogonal to each other;
• a temporal waveform detection step of detecting, by a streak camera, temporal waveforms of respective intensities of the first polarized light component and the second polarized light component of the probe light output from the polarizing beam splitter and of the pump light;
• and
• an analysis step of performing spectroscopic measurement of the sample based on, out of the temporal waveform of the intensity of each of the first polarized light component and the second polarized light component of the probe light detected by the streak camera, a temporal waveform in a period including a time at which the pump light is detected by the streak camera.

A terahertz wave spectroscopic measurement method comprising:

• a terahertz wave generation step of irradiating a sample with pulsed light output as pump light from a pump light source, and generating a terahertz wave when the sample is processed;
• a modulation step of inputting the terahertz wave to a terahertz wave detection element, inputting probe light to the terahertz wave detection element over an input period of the terahertz wave, and outputting the probe light with polarization modulation according to an electric field of the terahertz wave by the terahertz wave detection element;
• a polarized light splitting step of splitting, by a polarizing beam splitter, the probe light output from the terahertz wave detection element and passed through a quarter wave plate into a first polarized light component and a second polarized light component orthogonal to each other;
• a temporal waveform detection step of detecting, by a streak camera, temporal waveforms of respective intensities of the first polarized light component and the second polarized light component of the probe light output from the polarizing beam splitter and of the pump light;
• and
• an analysis step of performing spectroscopic measurement of the sample based on, out of the temporal waveform of the intensity of each of the first polarized light component and the second polarized light component of the probe light detected by the streak camera, a temporal waveform in a period including a time at which the pump light is detected by the streak camera, and monitoring a processing status of the sample.