| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical delay element that does not cause a loss or a reliability problem and is more compact than the conventional optical fiber delay line, while having a band width wider than the known conventional microresonance device. <P>SOLUTION: An optical delay line is formed of the coil of optical fiber (in many cases microfiber), where the radius of the optical fiber is greater than the wavelength λ of the propagating signal and the radius R of the coil is selected, in consideration of the radius of the optical fiber, to limit propagation loss by minimizing coupling between adjacent turns of the coil. The difference in dimension between the fiber diameter and wavelength prevents the mode propagating along one turn from coupling into an adjacent turn. Modal intensity at the interface between a central core rod and the coil is minimized when the radius of the fiber satisfies the predetermined condition. <P>COPYRIGHT: (C)2010,JPO&INPIT |
