title: Heterodyne interferometer scheme using a double pass in an acousto-optic modulator.
abstract: We introduce a heterodyne interferometer scheme utilizing the double-pass arrangement of the deflected beams of an acousto-optic modulator. To prove our new idea, the interferometer has been applied for measuring small amplitude vibrations. The output intermediate frequency signal from the interferometer is processed by using an I/Q demodulator. In theory, it can provide the quantum noise limited sensitivity, whereas, in our present Letter, the sensitivity of the phase measurement is limited by the resolution of the 16 bit A/D converter used for processing the I/Q signals. Details of our interferometer scheme are discussed.
authors.affiliation: Department of Physics, Sogang University, Seoul, Korea.
authors.forename: Youngkyu
authors.initials: Y
authors.lastname: Park
authors.forename: Kyuman
authors.initials: K
authors.lastname: Cho