Birefringence measurements of silicon samples through scanning an external cavity

Laser interferometric gravitational wave detectors, such as LIGO, Virgo, and KAGRA, measure the stretching and squeezing of space time between mirrors made of glass or crystal. Any birefringence in the mirror materials can cause optical loss and additional noise in the detectors. At the Albert Einstein Institute in Hanover, Germany, Krüger et al have set up a birefringence experiment based on a silicon scanning cavity. We are setting up a similar experiment based on scanning an external cavity in which silicon samples will be placed. We will present the experimental setup, any preliminary data, and expected outcomes.