Direct measurement of birefringence in ion-exchanged planar waveguides

Abstract
A direct measurement of the birefringence of a planar waveguide obtained by Na+-K+ ion exchange was performed with a double Lloyd interferometer. The results are compared with those obtained by a round-robin test involving the same sample. Birefringence of as much as Delta n = (2.0 +/- 0.2) x 10(-3) was measured