| 摘要 |
<p>PROBLEM TO BE SOLVED: To make an optical branching device able to freely divide input light two parts at an arbitral radio and output without giving a difference in delay between the divided and outputted lights. SOLUTION: In the device, a double refraction element for separation 10, a double refraction element for optical path control 12, a double refraction element for synthesizing 14 are arranged and a polarized wave rotating means 16 and a variable polarized wave rotor 18 are arranged between the double refraction element for separation and the double refraction element for optical path control, a distributing and equalizing means 30 and a polarized wave control means 20 are arranged between the double refraction element for optical path control and the double refraction element for synthesizing, thus the optical division ratio can be adjusted according to the control of the rotation angle in the polarized wave direction with the variable polarized wave rotor. In this case, the difference in the delay between divided output lights is eliminated by adding a part for correcting the difference in the optical paths (a distributing and equalizing means) to the double refraction element for optical path control which may cause the inequality of distribution. Further there is a composition in which the double refraction element for optical path control which may cause the inequality of distribution is changed into a optical path control means in which the distribution is equalized.</p> |
