| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an optical switch element which can perform the switching operation of high speed and high on-off ratio with high efficiency without depending on the polarized state of signal light. SOLUTION: A polarized light separation part 53 separates control light 51 into two linearly polarized light beams intersecting perpendicularly, and the polarized light direction of only one polarized light of the separated two polarized light beams is rotated to match another polarized light direction by a polarized light characteristics adjustment part 54. Thereafter, both polarized light is changed into circularly polarized light, and circularly polarized light is condensed to two points on a planar semiconductor light element 56. The polarized light separation part 53 separates signal light 52 into two linearly polarized light beams intersecting perpendicularly, and the polarized light direction of only one polarized light of the separated two polarized light beams to match another polarized light direction by the polarized light characteristics adjustment part 54. Thereafter, two linearly polarized light beams are condensed, respectively to two points to which the control light 51 on the planar semiconductor light element 56 is condensed, and switching is performed by changing the absorption characteristics of a semiconductor multiplex quantum well layer 14 contained in the planar type semiconductor light element 56 at the two points.</p> |
