Effect of some refractive index modifiers on both numerical aperture and mechanical strength of fluorozirconate fibres

Abstract

Abstract The effect of incorporating large amounts of some fluoride additives such as LiF, PbF2, HfF4 on both the numerical aperture and the mechanical strength of ZrF4 based glass fibres has been investigated. Fibres with core-cladding refractive index difference as high as 65 × 10−3 have been achieved with appropriate glass compositions. The tensile strength of multimode fibres tends to decrease from about 600 to 400 MPa with increasing PbF2 or HfF4 glass content, and high numerical aperture-small core diameter single mode fibres with strength within 500–550 MPa are achievable.