TIME-DOMAIN SPECTROSCOPE FOR HIGH-SPEED AND SENSITIVITY MEASURE BASED ON LIGHT-BIAS DOUBLE FREQUENCY MODULATION

摘要

PURPOSE: A time-domain spectroscope capable of high-speed and high-sensitivity measurement is provided to adapt an optical delay device using a cheap ultrasonic piezo linear motor, thereby reducing time required for measuring a THz spectrum. CONSTITUTION: A time-domain spectroscope(100) comprises a beam splitter(110), a THz wave detection member(170), a first optical system(120), a modulator(130), an optical delay device(140), a THz wave generating element(150), a second optical system(160), and a measuring device(180). The beam splitter splits lasers, thereby generating first and second lights. The first optical system makes the first lights incident into the THz wave detection member. The modulator modulates the second lights into a first frequency. The optical delay device delays the modulated lights. The THz wave generating element is biased by electrical signals of a second frequency and generates corresponding THz waves with respect to the incidence of the delayed lights. The measuring device measures a change in the THz wave emitted by the THz wave detection member.