title: Homodyne interferometry with quadrature fringe detection for absolute gravimeter.
abstract: An absolute gravimeter is based on interferometric displacement measurement during repeated free falls of a target mirror in a high vacuum. A suitable homodyne quadrature laser interferometer is developed and reported. Standard deviation of the mean absolute gravity value in a typical two-day measurement session is less than 1×10⁻⁸ m/s². Additionally, digital demodulation of the interference signal using a 90° phase-shift filter based on the Hilbert transform is presented. A combination of optical and digital quadrature phase shifts is shown to be helpful to improve accuracy in homodyne interferometers with the accelerated target mirror.
authors.forename: Sergiy
authors.initials: S
authors.lastname: Svitlov
authors.forename: Akito
authors.initials: A
authors.lastname: Araya