Fibre optic communication systems use optical fibres and the light they transmit to convey information. These systems offer numerous advantages, such as high transmission capacity and excellent confidentiality. The commercialisation of fibre optic amplifiers has made long-distance fibre optic communication truly feasible for the fibre optic communication industry.
      Erbium-doped optical fibres contain a small amount of erbium ions (a rare earth element) doped into quartz optical fibres. These fibres offer advantages such as a wide gain bandwidth, low noise and high gain, and are widely used in various types of optical fibre amplifier. The Changjin series of erbium-doped and polarisation-maintaining erbium-doped fibres provide diverse options for conventional applications with different gain levels, such as 7 dB, 14 dB, 30 dB, 50 dB and 80 dB. They also offer optimal solutions for special applications requiring ultra-high absorption.