with the present invention the pair of faraday rotators comprises a latched faraday rotator 202 which comprises a permanent magnetic garnet the latched faraday rotator 202 is bi substituted with a thickness which is enough to achieve about a 45 degree rotation at a given wavelength such as 1550 nm the pair of faraday rotators also comprises a switching faraday rotator 204 which comprises a faraday rotator 211 mounted within a ferrite core 212 and an electric coil 213 surrounding the ferrite core 212 a current may be provided to the electric coil 213 creating a magnetic field the current produced magnetic field is enhanced by the ferrite core 212 which is large enough to cause the faraday rotator 211 to rotate a polarization direction of a light either about 45 degree clockwise cw or counter clockwise ccw depending on the direction of the current the switching faraday rotator 204 should have a small saturation field so that only a small current is needed the faraday rotator 211 can be either non latched or latched with a hysteresis loop for a latched faraday rotator 211 only a pulsed current is needed to set the polarization by combining the latched faraday rotator 202 and the switchable faraday rotator 204 the polarization angle of a light traversing therethrough can be either about 0 degrees when the magnetic field in the switching faraday rotator 204 is opposite to that of the latched faraday rotator 202 or about 90 degrees when the magnetic field in the switching faraday rotator 204 is in the same direction as in the latched faraday rotator 202 the position of the latched faraday rotator 202 and the switching faraday rotator 204 can be exchanged without affecting the output fig3 illustrates a combination of a pair of.