| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To realize miniaturization and cost reduction of a polarization dependent type optical device by using one piece of an expensive birefringence crystal and an inexpensive thin type polarizer and suppressing the number of another optical elements to the minimum to make the optical device function. <P>SOLUTION: A birefringence element 14 for controlling an optical path controlling the shift of the optical path according to the polarization direction of inputted light and having a parallel surface structure, a±45°variable Faraday rotator 12 and the polarizer 10 are disposed in a row, two ports and one port are set on the side of the refringence element for controlling optical paths and on the side of the polarizer, respectively, and linearly polarized wave holding fibers 16 are disposed in the respective positions of the ports. A 1×2 or a 2×1 optical switch function is made to be presented by switching polarization rotation to either of±45°by using the±45°variable Faraday rotator. A three port non-circulation type optical circulator function can be also incorporated in the optical device by using a 45°fixed Faraday rotator instead of the±45°variable Faraday rotator. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
