We all know that optical communication is a high-tech product, so do you know what band of laser diode it mainly uses? Let's take a look at it from the perspective of Xiaobian.

850 nm

This section is mainly equipped with VCSEL laser diode, which is often used in:

Interconnection of servers in data center and short-distance communication in computer room (tens to hundreds of meters)

1310 nm, the most commonly used band for metropolitan area networks and access networks.

The characteristics of 1310nm are very practical:

Optical fiber dispersion is small, and the signal is not easy to "faint"

Commonly used DFB/FP laser, the cost is moderate.

10km, 20km and 40km are all common.

Many operators' optical cat uplink ports are 1310nm, and generally use DFB as the transmitting end and the receiving end is equipped with 1490nm downlink.

1550 nm, the main force of long distance and large bandwidth.

This section is the "trump card band" of optical communication for a simple reason:

The loss of optical fiber is the lowest at 1550nm, about 0.2dB/km.

You can use **EDFA fiber amplifier * * with strong and stable gain.

Suitable for 80km, 100km or even hundreds of km links.

DWDM (Dense Wavelength Division) is basically in C-band (1530-1565nm) and L-band (1565-1625nm).

Waveband for DWDM (1530~1625nm)

DWDM in order to plug more wavelengths (each path is a laser), generally choose:

C-band (1530-1565nm)

L-band (1565-1625nm)

Laser usually uses narrow linewidth DFB or external cavity laser (ECL).

The line can run to hundreds of G or even T capacity.

These are the laser diodes that are mainly used in optical communication. I hope you will have some help after reading them.