| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polarization-independent optical isolator in which the temperature rise of a Faraday rotator can be suppressed in spite of incidence of high-output light. <P>SOLUTION: The polarization-independent optical isolator includes a Faraday rotator 3 comprising a pair of wedge type birefringent crystal plates 1 and 5 made of a LiNbO<SB POS="POST">3</SB>single crystal and a magnetic garnet single crystal, and has a sapphire single crystal plate joined to each light-transmissive surface of the Faraday rotator. A light-transmissive surface of each sapphire single crystal plate is formed so as to be offset from a c-plane of the sapphire single crystal plate, and an incident angle θa on the sapphire single crystal plate of virtual light expressed by a bisector of an angle formed between optical axes of ordinary light and extraordinary light separated from each other by the wedge type birefringent crystal plates and an offset angle θoff from the c-plane of the sapphire single crystal plate are set within prescribed ranges so as to meet the condition that both the ordinary light and the extraordinary light form angles of 0.74° or less with a c-axis of the sapphire single crystal plate after impinging on the sapphire single crystal plate. <P>COPYRIGHT: (C)2013,JPO&INPIT |
