| 摘要 |
PURPOSE: A heterodyne interferometer using an acoustic optical modulator is provided to simplify a structure of a whole system by using a single AOM(Acoustic Optical Modulator) and small numbers of optical systems because the AOM is constituted as a double-pass. CONSTITUTION: A heterodyne interferometer using an acoustic optical modulator comprises a light source(400), a polaroid beam splitter(410), an acoustic optical modulator(420), an AOM driving unit(430), a first mirror(450), a second mirror(454), a mirror driving unit, a QWP(Quarter-Wave Plate)(440), a photo-detector, and a demodulator(470). The polaroid beam splitter radiates or reflects irradiated light according to a polarization state. The acoustic optical modulator divides the light passed through a PBS(Polaroid Beam Splitter) and irradiated into a first ray and second ray which frequency is biased as much as a driving frequency(f_RF). The AOM driving unit drives the AOM by a driving frequency. The first mirror reflects the first ray again along an irradiation path of the first ray so that signal beam is offered. The second mirror reflects the second ray again along an irradiation path of the first ray so that reference beam is offered. |
