Birefringence metrology analysis for CaF₂

Various metrology tools are available for characterizing the birefringence of optical materials. Of particular interest to Corning Incorporated is the birefringence characterization of Corning CaF₂. Some instruments employ a polarization camera for instantaneous, high spatial resolution measurements (<0.1mm across optics larger than 100mm), while others use a rotating analyzer to achieve higher spatial resolution at the cost of longer measurement times. Additionally, pencil beam instruments offer ~0.5mm resolution and rapid data acquisition speeds (~50kHz) over a broad spectrum, including the DUV, but average out fine details.