一、绪言众所周知,石英单模光纤可以有极低的损耗。目前这种光纤在1.2～1.7μm波段内损耗巨小于0.5db/Km,而在 1.55μm时的最小损耗已低达 0.2db/Km;另一方面,单模光纤因无模式色散故可有很宽的带宽,可达10～数百 GHz·Km。因此,石英单模光纤可以充分发挥石英光纤固有的低损耗、宽频带潜力,可以在长中继距离、大容量的通信系统中用作优良的传输介质。许多专家也都认为低损耗宽频带 First, the introduction As we all know, quartz single-mode optical fiber can have very low loss. At present, this type of optical fiber consumes a huge loss of less than 0.5db / Km in the band of 1.2-1.7μm, while the minimum loss of 1.55μm is as low as 0.2db / Km. On the other hand, the single mode fiber can have very low loss due to modeless dispersion Wide bandwidth, up to 10 ~ hundreds of GHz · Km. Therefore, quartz single-mode optical fiber can give full play to the inherent low loss, wideband potential of quartz optical fiber, and can be used as an excellent transmission medium in long-relay distance and large-capacity communication systems. Many experts also consider low-loss broadband