| 摘要 |
PURPOSE:To form the optical coupler with a low loss and a long life by using an optical fiber provided with two parallelly extended cores, providing the stress giving part to make the refractive index equal to the clad part at both sides of the first core and providing the stress giving part to make the refractive index smaller than the clad part at both sides of the second core. CONSTITUTION:One side polarization holding optical fiber 23 is the optical fiber to make a refractive index ns of stress giving parts 13 and 14 smaller than a refractive index n2 of a clad part 17. Other side polarization holding optical fiber 24 is the optical fiber to make the refractive index ns of stress giving parts 15 and 16 equal to the refractive index n2 of the clad part 17. Respective linear polarization lights are made incident on the first core 11 and the second core 12, and thereby, the linear polarization light of the first core is linked to the second core, and multiplexed as the mode orthogonal to the linear polarization light in the second core. |
