Homemade open-source full-Stokes polarimeter based on division of amplitude

We present an open-source homemade Stokes polarimeter for real-time determination of the state and degree of polarization of a light beam by measuring all four Stokes parameters. Our design uses standard, commercially available optical components, mounted on a 3D printed base. Our user-friendly software allows visualization of the measured polarization state on the Poincaré sphere. The accuracy of the polarimeter largely depends on the quality of the chosen optical components, which in turn affects its price. Depending on this choice, the instrument can be used for applications ranging from simple didactic purposes to more accurate, research-grade measurements. In our case we estimate an accuracy better than 1.60º in the determination of the state-of-polarization and 4.2% in the degree-of-polarization. We find the instrument to be particularly useful for fast and efficient stabilization of polarization-maintaining optical fibers, representing a low-cost alternative to more expensive commercial instruments.