Relative Stress-Optical Coefficients Of Some Nbs Optical Glasses

The relative stress-optical coefficients of 27 optical glasses at the National Bureau of Standards have been determined. The glasses were loaded in compression, and the amount of birefringence, as measured with a polarimeter, using a quarter-plate compensator. The stress-optical coefficients determined for the crown glasses ranged between+ 2.95 and + 1.82 brewsters. For the flint glasses, a regular variation of the stress-optical coefficient with 8% of lead oxide found with values ranging from + 3.18 to - 1.16 brewsters.