| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a polarization-independent optical isolator which is small-sized and is superior in isolation characteristics.SOLUTION: Between first and second ferrules (21a and 21b), a first collimate lens 22a, a first birefringence plate 11a, a first Faraday rotator 12a, a second birefringence plate 13a, a third birefringence plate 11b, a second Faraday rotator 12b, a fourth birefringence plate 13b, and a second collimate lens 22b are arranged on an optical axis 50. Each of the birefringence plates has one surface being a surface 31 perpendicular to the optical axis and has the other surface being an inclined surface 32. In each of pairs of the first and second birefringence plates and third and fourth birefringence plates, the perpendicular surfaces face each other and downward inclination directions (41a and 43a, and 41b and 43b) of the inclined surfaces form 180°. Inclination directions of the inclined surfaces of the second and third birefringence plates form 90°, and inclination directions (70a and 70b) of end surfaces of the first and second ferrules form 180°, and inclination directions of the first ferrule and the first birefringence plate form 45°, and those of the fourth birefringence plate and the second ferrule form 45°.</p> |
