BRAGG GRATINGS MULTIPUSLE INSCRIPTION EFFICIENCY DEPENDENCE ON ANGULAR POSITION OF ELLIPTICAL STRESS CLADDING IN BIREFRINGENT OPTICAL FIBERS

Subject of Research.The paper deals with mutlipulse inscription comparative results of the type IBragg gratings in the birefringent optical fiber with elliptical stress cladding and increased GeO2 concentration at different birefringence axes positions. Method. The gratings were inscribed by the phase mask method. The excimer laser Coherent COMPexPro 102F, working with the gas mixture KrF (248 nm), was used as the radiation source. The phase mask Ibsen Photonics with a period of1065.3 nm was used. Main Results.The results have shown that the multipusle inscription is more effective and has better dynamics when the plane containing the fiber axis and its slow birefringence axis is parallel to the writing radiation incidence plane containing the fiber axis. Practical Relevance. Theresearch results give the possibilityto make recommendations for the multipulse Bragg gratings inscription efficiency enhancement in the specialty birefringent fibers. The pre-inscription positioning of birefringence axes also makes it possible to reduce the polarization fading that is the noise source in phase interferometric sensors.