title: High resolution heterodyne interferometer based on time-to-digital converter.
abstract: A new heterodyne interferometer is presented, which adopts time-to-digital converter (TDC) measuring the time intervals of zero crossings of heterodyne signal for phase demodulation. Thanks to the 0.1 ns time resolution of TDC and linear phase demodulation, it can achieve high resolution and avoids nonlinear measuring distortion in other indirect high precise phase demodulation methods, such as pulse width modulation (PWM) and in-phase∕quadrature (I∕Q) method.
authors.affiliation: Department of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Zhangcai
authors.initials: Z
authors.lastname: Long
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.forename: Meirong
authors.initials: M
authors.lastname: Zhao