把光作为载波用的光通信,在半导体激光器的室温连续振荡和低损耗的光导纤维实现后,进入了更实用的阶段。世界各地正在稳步而顺利地进行着大规模光通信网络的建设工作。今后,光导纤维将占据新设通信线的主流地位。光导纤维比电气通讯电缆的直径细,重量轻,无电磁感应干扰;它损耗低.频带宽、性能优异,价格不大取决于频带特性,即频带宽度600兆赫·千米的多 Light as a carrier for optical communications, semiconductor lasers at room temperature continuous oscillation and low loss of optical fiber to achieve a more practical stage. The construction of large-scale optical communications networks is steadily and smoothly carried out all over the world. In the future, optical fibers will occupy the mainstream of the newly established communications line. Optical fiber is thinner, lighter, and less susceptible to electromagnetic interference than electrical communication cables; it has low loss, good bandwidth, excellent performance and low price depending on band characteristics, ie, a bandwidth of more than 600 MHz • km