Developement of lead free zero photoelastic glasses based on high precision measurement for photoelastic constant

2015 Fiscal Year Final Research Report

• Project/Area Number: 25820333
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Inorganic materials/Physical properties
• Research Institution: Ehime University
• Principal Investigator: SAITOH Akira 愛媛大学, 理工学研究科, 准教授 (80431328)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 光弾性定数 / リン酸塩ガラス

Outline of Final Research Achievements

For an optical fiber current sensor utilizing very small birefringent glass having zero photoelastic constant (PEC) is essential to keep very low levels of the noise due to photoelastic effect. Since a rotation angle of linearly polarized light propagated in the fiber is in proportion to a magnetic field strength generated by a current. To date, high PbO containing silicate glass fiber is realized for the fiber typed current sensor. However, other glasses made by Pb-free composition should be found from a point view of environmental friendly materials.
We have developed very small birefringent zinc tin borophosphate glasses. The boro-phosphate composition line without Pb provides both very low PEC and improved water durability. Some glass compositions with nearly zero PEC (less than |0.01 × 10-12| Pa-1) are obtained. The structure revealed by micro-Raman and MAS-NMR spectroscopies and the possibility to make an optical fiber using the zero PEC composition are studied.

Free Research Field

ガラス工学