[en] A small fixed-mirrors Michelson interferometer has been suggested for VIRGO. The experimental results are excellent and fully confirm the adequacy of the method. The minimum angular misalignment that can be detected in the present set-up is 10 nrad

No abstract available

[en] In this paper we will prove that the Lorentz factor doesn't exist on the relative motion. In fact this factor is the result of a wrong calculation of Michelson. His mistake was approved by Lorentz and other physicists, including Einstein. Michelson in order to implement his idea with his interferometer in 1881, made the following mistake: he made the calculation according to the only principle of relativity which was known by physics--the Galileo principle, but he didn't faithfully apply this principle. In this paper, the principle of Galileo will be implemented exactly to Michelson's experiment and the result will show us that physics doesn't need the postulates of the year 1905.

[en] Laser interferometers may detect gravitational waves by sensing the strain in space produced by their passage. The resultant change in intensity of an interference fringe must be observable against a background noise due to the statistical fluctuations in the number of detected photons. Optimization of the detector sensitivity thus involves devising an optical system which both maximizes the signal and minimizes the noise. This is attempted in the various arrangements known collectively as light recycling. Here, the performance of these systems is quantitatively assessed. Standard or broadband recycling functions essentially by making efficient use of the available light, but it is shown that it may also be made to further enhance the sensitivity within a narrow bandwidth, becoming tuned recycling. This works, as do all the narrow-band variants, by arranging for both the laser light and a gravitational-wave-induced sideband to be resonant in the optical system. The original narrow-band system, resonant recycling, can also be made broadband; the various sensitivity-bandwidth combinations, together with the tuning properties of such a system, are discussed

[en] In September 2015 the Advanced LIGO detectors inaugurated the era of gravitational-wave astrophysics with the observation of GW150914. In this proceeding, I will describe the upgrade that made the detection possible, review the binary black hole observations of the first a LIGO observing run, and discuss plans for the future.

[en] In this paper, we report a new method of thermal characterization of optical fibers using wavelength-sweeping interferometry and discuss its advantages compared to other techniques. The setup consists of two temperature-stabilized interferometers, a reference Michelson and a Mach-Zehnder, containing the fiber under test. The wavelength sweep is produced by an infrared tunable laser diode. We obtained the global phase shift coefficients of a large effective area fiber and gold-coated fiber optics with a 10^-7 accuracy.

No abstract available

[en] The upgrade of Virgo to Advanced Virgo has been completed in 2016. The detector is now being commissioned, with the goal of starting taking data with the two LIGO interferometers during summer 2017.

[en] This paper summarise some of the achievements of optical interferometry in its 100 years of existence. It is shown how over the decades, developments in optics, lasers, electronics and quantum mechanics have led to dramatic improvements in sensitivity, with the most recent developments aiming at a δL/L of 10^-12. In addition, digital image processing and laser stabilisation techniques were combined to analyse optical surfaces with a resolution of 1/500 of a fringe. Some of interferometer applications are discussed and these include radio astronomy, laser gyroscopes, the visualisation of flows and the diagnostic of laboratory plasmas. 18 refs., 2 figs

[en] Published in summary form only