Techniques and devices for measuring stress, strain, or temperature based on polarization crosstalk analysis in birefringence optical birefringent media including polarization maintaining fiber. The disclosed techniques and devices can be implemented to measure polarization crosstalk distribution in polarization maintaining fiber by placing the PM fiber in a 1-dimensional or 2-dimensional configuration for sensing temperature, stress or strain in the PM fiber at different locations along the fiber with a high spatial sensing resolution. In some implementations, the disclosed techniques and devices can be implemented to simultaneously measure stress, strain and temperature from analyzing the probe light. For example, both temperature and stress/strain can be simultaneously measured by using the same sensors to extract and separate temperature measurements from stress/strain measurements.