Structure of optical module
The transmitting part is: input the electric signal with a certain code rate, drive the LD or led to emit the corresponding rate modulation optical signal after being processed by the internal driving chip, and the internal optical power automatic control circuit is provided to keep the output optical signal power stable. The receiving part is: a certain bit rate of optical signal input module by the optical detection diode into electrical signals. After the preamplifier, the corresponding code rate electrical signal is output.
Classification of optical modules
It includes optical receiving module, optical transmitting module, optical transceiver integrated module and optical forwarding module.
a. The main function of the optical transceiver integrated module is to realize photoelectric / electro-optic conversion, including optical power control, modulation and transmission, signal detection, IV conversion and limiting amplification and judgment regeneration. In addition, it also has anti-counterfeiting information query, TX disable and other functions. The common functions are: SFF, SFF +, GBIC, XFP, 1x9, etc.
b. In addition to the photoelectric conversion function, the optical forwarding module also integrates many signal processing functions, such as MUX / demux, CDR, function control, sexual energy acquisition and monitoring. The common optical forwarding modules are: 200 / 300pin, xenpak, and X2 / xpak.
c. Optical transceiver module, English name transceiver, is an important device in optical fiber communication system.
Transmission rate of optical module
Optical module has developed from 155Mb / s to 10Gb / s at the beginning, and then the speed of optical module has increased to 40gmb / s and 100gmb / s, and 400gmb / s optical module has been successfully developed. It is believed that the optical module will grow faster and faster with the continuous expansion of the market in the future.
Packaging method of optical module
Driven by technology upgrading, cost reduction and other factors, optical modules continue to be "high-speed, miniaturization and integration".
25g laser chip technology is used in 100g optical module. According to different packaging methods, 100g optical module mainly includes CFP, CXP and qsfp28. Qsfp28 is a new generation of 100g optical module. Among the 40g optical modules, CFP and qsfp are the main packaging forms, and 40g qsfp + optical modules are widely used. The main packaging methods of 10G Optical module include xenpak, X2, XFP, SFP, and SFP +, among which the SFP + optical module is the best.
Transmission distance and central wavelength of optical module
The transmission distance of optical module can be divided into short distance, medium distance and long distance. The transmission distance of optical module can be divided into short distance, medium distance and long distance. Generally speaking, 2km and below are short distance, 10-20K is medium distance, 30km, 40km and above are long distance.
The central wavelength refers to the optical band used for optical signal transmission. At present, there are three kinds of central wavelengths of optical modules: 850nm, 1310nm and 1550nm.
850nm band: mostly used for short distance transmission of ≤ 2km
1310nm and 1550nm waveband: it is mostly used for medium and long distance transmission, and more than 2km transmission.
The function of optical module
1. As an optical interface, it receives light-emitting signal and connects with optical fiber and tail fiber
2. The optical signal is introduced into the light board and processed in the light board
3. The reason why the optical module is used on the optical board instead of directly fixing the optical interface on the optical board is that the optical module can ensure that the optical board can adapt to various optical interfaces. When SC, FC, LC tail fiber connection is adopted, the corresponding optical module can be replaced. A kind of
4. When the optical module is broken, it is easy to replace
Digital Diagnostic Functions
The following digital diagnostic characteristics are defined over the normal operating conditions unless otherwise specified.
Parameter | Symbol | Min. | Max | Unit | Notes |
Temperature monitor absolute error | DMI_ Temp | -3 | 3 | degC | Over operating temp |
Supply voltage monitor absolute error | DMI _VCC | -0.15 | 0.15 | V | Full operating range |
RX power monitor absolute error | DMI_RX | -2 | 2 | dB | |
Bias current monitor | DMI_ bias | -10% | 10% | mA | |
TX power monitor absolute error | DMI_TX | -2 | 2 | dB |
Application of optical module:
Video optical transceiver: generally, 1 * 9 single-mode optical module is used, and some high-definition optical transceiver will also use SFP optical module.
Optical fiber transceiver: 1 * 9 and SFP optical module are adopted
Switch: GBIC, 1 * 9, SFP, SFP +, XFP optical modules are used for switching opportunities
Optical fiber Router: generally uses the SFP optical module
Optical fiber network card: 1 * 9 optical module, SFP optical module and SFP + optical module are used
Optical fiber high-speed ball machine: using SFP optical module
Base station: in the mobile communication system, the equipment connecting the fixed part and the wireless part, and connecting with the mobile station through the wireless transmission in the air, adopts the optical modules of SFP and XFP
Tunnel traffic monitoring.
2015-2020 10G/40G/100G optical module market size