Compensation mechanism of polarization-independent reflection structure based on two magneto-optical crystals and two mirrors

We provide, to our knowledge, the first experimental demonstration of polarization-independent reflection structure, which is based on two magneto-optical crystals with 90° rotatory angles and two mirrors without depolarization. The experiment shows that the polarization fidelity achieved about 99.98%. We also find out that even the rotatory angles of magneto-optical crystals are not 90°, when the two rotatory angles are near to 90°, the closer they are, the higher polarization fidelity is. This characteristic can be very important and useful for engineering implementation. It is also approved in theory and experiment.