Reducing symmetric polarization aberrations in a molded glass lens by annealing

摘要

Mueller matrix imaging polarimetry was used to study stress in a series of a high numerical aperture molded glass lenses. An interesting radially symmetric retardance was found which resembled the polarization aberration induced by coatings. Upon investigation the source of the polarization aberration is traced to a remarkably symmetric radial stress birefringence in the glass believed to arise during fire-polishing of the surfaces. While annealing the lenses relieves much of the stress birefringence, reducing the retardance of the lenses by a factor of five, the lenses remained unusable for critical polarization applications.