The manual polarization controller utilizes stress-induced birefringence to alter the polarization in a single-mode fiber. With each of the three paddles acting as a fractional waveplate, complete coverage of the Poincaré. We offer compact, in-line polarization controllers for Ø250 µm bare fiber or Ø900 µm tight-buffer fiber. Each device consists of a rotatable fiber squeezer and two fiber holding clamps. The first. Therefore, it often doesn't help that much to adjust a polarization state, e.