| 摘要 |
<p>A single mode optical fiber includes, from the center towards the periphery, a central core, an intermediate cladding, a depressed trench, and an external optical cladding. The central core has a radius r 1 and a positive index difference ”n 1 with the optical cladding; the intermediate cladding has a radius r 2 and a positive index difference ”n 2 with the optical cladding, wherein ”n 2 is less than the index difference ”n 1 of the core. The depressed trench has a radius r 3 and a negative index difference ”n 3 with the optical cladding. The optical fiber has a mode field diameter (MFD) between 8.6 µm and 9.5 µm at a wavelength of 1310 nanometers, and for a wavelength of 1550 nanometers, the fiber has bending losses less than 0.25 x 10 -3 dB/turn for a radius of curvature of 15 millimeters. The length of fiber required for the attenuation of the LP11 mode to reach 19.3 dB at a wavelength of 1260 nanometers is less than 90 meters. Such a fiber can be used in a difficult environment such as miniaturized optical boxes.</p> |
