| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical attenuator capable of low-voltage drive and having excellent optical loss characteristic.SOLUTION: The present invention is an optical attenuator 101 created by arranging a polarization unit 110a including two birefringent elements (10a, 30a), along an axis z in order from the front, between optical fiber collimators (40a-40b) facing back and forth in an xyz orthogonal coordinate system in which a direction z is an optical axis 50, an electro-optical element 20 for imparting, to a linear polarization light from the front, a prescribed phase difference that corresponds to a voltage between electrodes (22-22) facing in a direction Y and emitting the light from the rear, and a light detection unit 110b including two birefringent elements (30b, 10b), wherein the polarization unit emits linear polarization light from first and second optical paths that separate input light from the front in parallel to an axis x, and the light detection unit makes light having traced the first and second optical paths from the EO element joined to the optical fiber Fb of the optical fiber collimator at the rear when the EO element is imparting either a 0° or a 180° phase difference. |
