In the field of modern communication, optical communication has become the main data transmission method. In optical communication systems, optical modules play a crucial role as key transmission components. At present, the mainstream optical modules on the market include Huawei, H3C, Cisco, Ruijie, FS, etc. Next, we will delve into the basic knowledge of optical modules.
Structure:
The optical transceiver integrated module is composed of optoelectronic devices, functional circuits, and optical interfaces. The optoelectronic devices include two parts: emission and reception.
The transmission part is: the input of a certain bit rate electrical signal is processed by an internal driver chip to drive a semiconductor laser (LD) or light emitting diode (LED) to emit a corresponding rate modulated optical signal. It is equipped with an automatic optical power control circuit inside to maintain stable output optical signal power.
The receiving part is: a certain bit rate optical signal is input into the module and converted into an electrical signal by the optical detection diode. After passing through the preamplifier, the corresponding code rate electrical signal is output, and the output signal is generally at the PECL level. At the same time, an alarm signal will be output when the input optical power is less than a certain value.
Optical module classification:
1, Classification by application:
Ethernet application speed: 100Base (100 Mbps), 1000Base (Gigabit), 10GE. The speed of SDH application: 155M, 622M, 2.5G, 10G.
2, Classification by laser:
ED, VCSEL, FP LD, DFB L.
3, Classification by wavelength:
850nm, 1310nm, 1550nm etc.
The working principle of the optical module:
An optical module is a device that converts electrical signals into optical signals or converts optical signals into electrical signals. It achieves the mutual conversion between light and electrical signals through an internal photoelectric converter (photodiode or laser). When an electrical signal is received, the optical module converts it into a corresponding optical signal and transmits it to the target device through fiber optics. When an optical signal is received, the optical module converts it into an electrical signal for processing by the target device.
Application of optical modules:
Optical modules are widely used in various fields of optical communication systems, including data centers, internet backbone networks, wireless base stations, etc. The following are some common application scenarios for optical modules:
1) Data center: In large-scale data centers, optical modules are used for high-speed data transmission to meet the fast communication needs between servers within the data center.
2) Internet backbone network: Optical modules play a key role in the backbone network of the Internet, used to achieve long-distance and high-speed data transmission.
3) Wireless base station: Optical modules are widely used in fiber optic post transmission systems of wireless base stations, transmitting signals from the base station to the antenna and achieving high-speed data exchange with mobile phones or other terminal devices.
Main parameters of the optical module:
1. Transmission rate:
The transmission rate refers to the number of bits transmitted per second, in Mb/s or Gb/s. Main speeds: 100 Mbps, Gigabit, 2.5G, 4.25G, and 10000Mbps.
2. Transmission distance:
The transmission distance of optical modules is divided into three types: short range, medium range, and long range. It is generally believed that distances of 2km and below are short distances, distances of 10-20km are medium distances, and distances of 30km, 40km and above are long distances.
The transmission distance of optical modules is limited mainly due to the certain loss and dispersion of optical signals when transmitted in optical fibers.
