| 摘要 |
PURPOSE:To reduce the coupling length of an optical fiber and to realize the optical fiber having polarization maintainability by selecting a standardized frequency in an optimum way when the quantity of double refraction is constant. CONSTITUTION:The figure is obtd. when the relation between the standardized frequency and the coupling length is measured while the specified quantity of the double reflection is maintained with the optical fiber formed concentrically with a circular core 1, an elliptical clad 2 and a jacket 3 into a concentrical circular shape. The figure shows the coupling length L measured by changing the core diameter or the refractive index of the core. The coupling length is short between 1.7-3.9 standardized frequencies and increases sharply outside said range. The optical fiber having high polarization maintainability is realized by selecting the standardized frequency between 1.7-3.9. |
