Showing papers by "Enrico Calloni published in 1994"
TL;DR: A digital fringe-counting technique is implemented to measure in real time the relative mirror displacement of a suspended Michelson interferometer with modulated optical path length for oscillations much larger than the laser wavelength.
Abstract: We implement a digital fringe-counting technique to measure in real time the relative mirror displacement of a suspended Michelson interferometer with modulated optical path length for oscillations much larger than the laser wavelength (λ). This provides the proper error signal for a servo mechanism that reduces the relative displacement within λ/2. The implemented technique does not require extra optics or polarizers and thus can be used for interferometric gravitational wave detectors as a starting procedure to get the system locked.
24 citations
TL;DR: In this article, a digital system for beam alignment is described, capable of achieving a beam alignment of 10 −9 rd Hz for frequencies above 1 Hz, based on the ability to diagonalize the feedback matrix for any complex servo-controlled subsystems included in large experiments.
8 citations
TL;DR: A prototype for the real-time control of the various degrees of freedom, based on VME architecture, is designed and tested, which is general enough to make it able to satisfy the different and stringent specifications of many physical and engineering applications.
Abstract: The automatic control of the interferometric Virgo antenna for gravitational wave detection requires a digital control system characterized by high-speed and low-noise. We have designed and are now testing a prototype for the real-time control of the various degrees of freedom, which is based on VME architecture. Its characteristics are general enough to make it able to satisfy the different and stringent specifications of many physical and engineering applications. >
2 citations