Algebraic cancellation of polarisation noise in fibre interferometers

Multiplexed fibre-optic sensors using ring interferometers

We describe a number of multiplexing techniques which may be used for fibre-optic sensors in which the sensing element is a ring resonator . The basic optical unit comprises a sensing ring resonator connected to a second interrogating ring resonator of nearly equal length, and illuminated by a source of short coherence length. A number of such units may be combined to form an array, using coher...

Phase and alignment noise in grating interferometers

Diffraction gratings have been proposed as core optical elements in future laser interferometric gravitational-wave detectors. In this paper, we derive equations for the coupling between alignment noise and phase noise at diffraction gratings. In comparison to a standard reflective component (mirror or beam splitter) the diffractive nature of the gratings causes an additional coupling of geomet...

Quantum Optical Noise in Advanced LIGO Interferometers

Quantum Noise in Gravitational-wave Interferometers

We present an overview of quantum noise in gravitational wave interferometers. Current gravitational wave detectors are modified variants of a Michelson interferometer and the quantum noise limits are strongly influenced by the optical configuration of the interferometer. We describe recent developments in the treatment of quantum noise in the complex interferometers of present-day and future g...

Single-polarisation mode in air-core holey fibre

An air-core holey fibre design that supports a single-polarisation circularly symmetric mode is presented. The mechanism that isolates the single polarisation, the advantages of the design and fabrication efforts to date will be discussed.