OPTICAL POLARIZATION MODULATOR AND OPTICAL TRANSMISSION DEVICE

摘要

The present invention comprises: a modulation unit (1) composed of a birefringent material and adapted to modulate the polarization of an inputted optical signal by changing the phase difference between discretely polarized waves, and to output the modulated signal; and a birefringent medium (2). The modulation unit (1) and the birefringent medium (2) are disposed so that the fast axis of the modulation unit (1) and the slow axis of the birefringent medium (2) coincide with each other, that the slow axis of the modulation unit (1) and the fast axis of the birefringent medium (2) coincide with each other, and that a polarization-modulated signal outputted by the modulation unit (1) is incident on the birefringent medium (2) and passes through the medium from the direction orthogonal to the plane constituted by the fast and slow axes of the birefringent medium (2). An optical signal of linearly polarized light having an angle of 45° relative to the discrete polarization axis of the modulation unit (1) is inputted to the modulation unit (1).