POLARIZING GLASS PLATE AND METHOD FOR MANUFACTURING SAME, POLARIZING GLASS PLATE SET FOR OPTICAL ISOLATOR, AND METHOD FOR MANUFACTURING OPTICAL ELEMENT FOR OPTICAL ISOLATOR

摘要

A method of manufacturing a polarizing glass sheet includes subjecting, while heating, a glass preform sheet containing metal halide particles to down-drawing, to thereby provide a glass member having stretched metal halide particles dispersed in an aligned manner in a glass matrix, and subjecting the glass member to reduction treatment to reduce the stretched metal halide particles, to thereby provide a polarizing glass sheet. A shape of the glass preform sheet during the down-drawing satisfies a relationship of the following expression:; L ₁ /W ₁≥1.0;where L₁ represents a length between a portion in which a width of the glass preform sheet has changed to 0.8 times an original width and a portion in which the width of the glass preform sheet has changed to 0.2 times the original width W₀, and W₁ represents a length equivalent to 0.5 times the original width W₀ of the glass preform sheet.