Optical cable manufacturers tell you: outdoor optical cables are mainly used in the interconnection between buildings and between remote networks. Due to the installation environment, it has stronger pressure resistance, corrosion resistance and greater tensile strength than indoor optical cables. And a thicker protective layer, mostly armor. Outdoor optical cables are divided into single-mode and multi-mode in transmission.

The core of single-mode outdoor optical cable is about 10μm, the propagation path is single, and there is no dispersion. Most of the light sources are lasers or laser diodes, and the attenuation of optical signals is much smaller than that of multi-mode outdoor optical cables. For example, at a distance of 1000 meters, the optical signal attenuation of a multi-mode outdoor optical cable may reach 50%, while the optical signal attenuation of a single-mode outdoor optical cable in the same distance is only 6.25%.

The multi-mode outdoor optical cable is named because it divides the propagation mode into multiple modes according to the working wavelength. The core diameter is 50 μm, and the light source is mostly LED or VCSEL (vertical cavity surface emitting laser). Due to the diversity of its transmission paths, its transmission bandwidth is dominated by modal dispersion compared to single-mode outdoor optical cables. Since the core diameter of the multimode outdoor optical cable is larger than that of the single mode outdoor optical cable and it is easier to combine with light sources such as LEDs, it has more advantages in many LANs. Therefore, multimode outdoor optical cables are mostly used in short-distance outdoor network connections.

The transmission distance is often the decisive factor in the selection of single-mode outdoor optical cables and multi-mode outdoor optical cables. When the transmission distance is short, multi-mode outdoor optical cables should be the first choice, because the LED transmitting and receiving devices used are far lower in cost. Laser required for single mode. The effective distance from the transmitter to the receiver of the multi-mode outdoor optical cable is about 8km, so when the transmission distance is greater than 8km, the single-mode outdoor optical cable should be selected.