Precision vibration measurement using differential phase-modulated homodyne interferometry

•A novel precision vibration measurement using differential phase-modulated homodyne interferometry is presented, in which an orthogonal linearly polarized laser source is constructed by using a DFB fiber laser and a fiber-coupled electro-optic phase modulator to improve the measurement range of amplitude and frequency.•The optical path drift and common-mode noise of the fiber can be differentially compensated by using an auxiliary monitoring signal.•By pre-scanning the wavelength of DFB laser, the ellipse fitting method can be realized to compensate the periodic nonlinearity of PGC demodulation without needing the object to move more than half a wavelength.