Since Sagnac’s first measurements of rotation with his interferometer there hasbeen a large amount of interest in making ever more sensitive measurementsusing a variety of different implementations of the Sagnac interferometer, [89,90, 91].There have been two main lines of development for Sagnac interferometers.Optical Sagnac interferometers, [89, 90, 91], aim to increase sensitivity by increasingthe path length of the two beams before they are coupled out of theinterferometer. There are two main schemes for achieving this, ring laser gyrosand optical fibre gyros. Multiple loops around the same physical area lead toan increased gyroscopic area.Matter-wave interferometers sensitive to the Sagnac effect are generally restrictedto Mach-Zehnder interferometers, [92, 93, 94]. One notable exceptionis the Sagnac interferometer of Arnold et al., [95]. Matter-wave interferometershave an intrinsic sensitivity much greater than optical Sagnac interferometers,due to the smaller velocity and wavelength of the particles compared to light.Matter-wave interferometers lose out to optical interferometers in that their enclosedarea is limited. Where the sensitivity of optical-fibre interferometers isvery easily scalable, for example by increasing the number of fibre loops, thesensitivity of matter-wave interferometers is not.Optical ring laser gyros can achieve sensitivities of 1.4 × 10−11 rad s−1 Hz−1/2,
đang được dịch, vui lòng đợi..