A Practical Method for Investigating and Measuring the Birefringence of Optical Glass

摘要

A practical method is presented for studying the annealing of optical glass. It is possible: 1. to survey at one glance the general distribution of the birefringence; 2. to determine quickly (in a few seconds) the value of the bi-refringence in arbitrarily selected points; 3. to trace, if this be deemed useful, the contour lines of the birefringence on the glass under examination. A suitable instrumental arrangement is described.