Spatial Distribution Of Birefringence Research Articles

Evaluation of the spatial distribution of birefringence in an optical‐fiber link

AbstractWe present a simple method of the calculation of spatial distribution of birefringence in an optical‐fiber link. This method is based on an analysis of the properties of the backscattered optical signal. The analytical results are compared with the numerical results, and excellent agreement is obtained. We demonstrate that the spatial‐birefringence distribution may be obtained from the calculation of the roundtrip Muller matrices derived from only two power‐evolution traces, corresponding to two different angles of the polarizer. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 147–149, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20234

On the origin of anomalous birefringence in grandite garnets

AbstractThe origin of anomalous birefringence of grossular–andradite (grandite) garnets from skarns in Mali and Russia was considered. The crystals had complex superposition of two phenomena: mismatch compositional strain (stress birefringence) and growth ordering of atoms (growth dissymmetrization). Study of the crystals using several experimental techniques (optical microscopy, microprobe analysis, X-ray diffraction topography and X-ray single crystal diffraction) as well as calculations of anomalous birefringence has confirmed this hypothesis. Depending on the crystal composition and growth conditions, the relative magnitude of each phenomenon controls the various optical effects. As a result one can see two groups of crystals which are found to have fundamentally different anomalous optical properties: crystals with low (<0.001) and high (0.001–0.015) values of birefringence. The spatial distribution of birefringence within each group is different and this fact is related to different mechanisms causing optical anomalies: stress birefringence and growth dissymmetrization for these two groups, respectively.

Frequency-derived distributed optical-fiber sensing technique: theory and characterization

Frequency-derived distributed optical-fiber sensing is a method for remote measurement of the spatial distribution of linear birefringence in an optical fiber, allowing a corresponding measurement of those external measurands that influence this birefringence. The method employs a pump-probe scheme, which, by use of the optical Kerr effect, generates an optical modulation of the probe beam, with a modulation frequency whose temporal variation maps the spatial distribution of birefringence. We provide a complete theoretical analysis of this method by using Jones calculus and graphic representation on the Poincaré sphere. The relevant characterization of the technique and some experimental results are also presented; these show good agreement with the theory.