title: Sensitivity-enhancing scheme of a polarimetric heterodyne sensor using a birefringent fiber loop.
abstract: In order to improve the sensitivity of a fiber-optic polarimetric sensor, a new scheme utilizing a birefringent fiber loop with midloop frequency shifters is proposed. In this scheme, heterodyne signals with an integral multiple-phase sensitivity can be obtained in the frequency domain. The validity of the scheme is confirmed experimentally by a bulk-optic configuration. One-order-of-magnitude improvement in sensitivity without changing the dynamic range is expected from the calculation of the signal-to-noise ratio, even in the case of a 40% excess loss in the optical loop.
authors.forename: K
authors.initials: K
authors.lastname: Arai
authors.forename: N
authors.initials: N
authors.lastname: Honda
authors.forename: T
authors.initials: T
authors.lastname: Mori
authors.forename: K
authors.initials: K
authors.lastname: Iiyama
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Ida