title: Advanced phasemeter for deep phase modulation interferometry.
abstract: We present the development of an advanced phasemeter for the deep phase modulation interferometry technique. This technique aims for precise length measurements with a high dynamic range using little optical hardware. The advanced phasemeter uses fast ADCs and an FPGA to implement a design of multiple single-bin Fourier transforms running at high sampling rates. Non-linear noise sources in the design were analyzed and suppressed. A null measurement with an optical beatnote signal using λ = 1064nm was conducted. It showed a sensitivity of 0.8μrad/√Hz below 10Hz and 13.3μrad/√Hz above, with a large dynamic range. The shown performance could enable the measuring of optical path lengths with sensitivities down to 0.14pm/√Hz and 2.3pm/√Hz, respectively, over several fringes in an interferometric setup.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Schwarze
authors.forename: Oliver
authors.initials: O
authors.lastname: Gerberding
authors.forename: Felipe Guzmán
authors.initials: FG
authors.lastname: Cervantes
authors.forename: Gerhard
authors.initials: G
authors.lastname: Heinzel
authors.forename: Karsten
authors.initials: K
authors.lastname: Danzmann