Optical module is composed of optoelectronic devices, functional circuits and optical interfaces.
The optoelectronic device includes two parts: transmitting and receiving. The transmitting end converts the electrical signal into an optical signal, and after transmitting it through the optical fiber, the receiving end converts the optical signal into an electrical signal.
structure
The transmitting part is: the electrical signal with a certain code rate is processed by the internal drive chip and then drives the semiconductor laser (LD) or light-emitting diode (LED) to emit a modulated light signal of the corresponding rate. The internal optical power automatic control circuit makes The output optical signal power remains stable.
The receiving part is: the optical signal of a certain code rate is input into the module and converted into an electric signal by the light detection diode, and the electric signal of the corresponding code rate is output after the preamplifier.
Classification
Divided by function: Including optical receiving module, optical transmitting module, optical transceiver module and optical forwarding module, etc.
The main function of the integrated optical transceiver module is to realize photoelectric/electro-optical conversion, including optical power control, modulation and transmission, signal detection, IV conversion, and limiting amplification judgment regeneration functions, in addition to anti-counterfeiting information query, TX-disable and other functions.
Common ones are: SFP, SFF, SFP+, GBIC, XFP, 1×9, etc.
In addition to the photoelectric conversion function, the optical forwarding module also integrates a lot of signal processing functions, such as: MUX/DEMUX, CDR, function control, sexual energy acquisition and monitoring functions. Common optical forwarding modules are: 200/300pin, XENPAK, and X2/XPAK, etc.
The optical transceiver module, the English name of the “transceiver”, is referred to as “optical module” or “optical module”. It is an important component in the optical fiber communication system.
According to the parameters
Pluggability: hot-swappable and non-hot-swappable
Package form: SFP, GBIC, XFP, Xenpak, X2, 1X9, SFF, 200/3000pin, XPAK.
Transmission rate: The transmission rate refers to the number of bits transmitted per second, in Mb/s or Gb/s. Optical module products cover the following main speeds: low speed, 100M, Gigabit, 2.5G, 4.25G, 4.9G, 6G, 8G, 10G and 40G.
Classified by package
According to the packaging, it can be divided into
1. SFP optical module
The small pluggable light emitting module (SFP) is currently the most widely used.
Optional wavelength: 850nm, 1310nm, 1490nm, 1550nm, CWDM, DWDM
Speed: 0-10Gbit/s
DDM: optional
2. SFP RJ45 electrical port module
Interface: RJ45, COPPER
Speed: 10/100/1000M adaptive, forced 1000M
DDM: optional
3. XFP optical module
XFP (10 Gigabit Small Form Factor Pluggable) is a hot-swappable, communication protocol-independent optical transceiver, used for 10G bps Ethernet, SONET/SDH, and fiber channel.
Optional wavelength: 850nm, 1310nm, 1270nm, 1330nm, CWDM, DWDM
Speed: 10Gbit/s
4. Gigabit Ethernet interface converter (GBIC) module
Optional wavelength: 850nm, 1310nm, 1490nm, 1550nm, CWDM, DWDM
Speed: 1. 25Gbit/s
5. GBIC RJ45 electrical port module
RJ45 electrical port small pluggable module, also known as electrical module or electrical port module.
Interface: RJ45, COPPER
Speed: 10/100/1000M adaptive, forced 1000M
DDM: optional
6. Folding SFP+ optical module
Optional wavelength: 850nm, 1310nm, 1270nm, 1330nm, CWDM, DWDM
Speed: 0-10Gbit/s
7. X2 optical module
Optional wavelength: 850nm, 1310nm, 1270nm, 1330nm, CWDM, DWDM
Speed: 10Gbit/s
8. XENPAK optical module
Optional wavelength: 850nm, 1310nm, 1270nm, 1330nm, CWDM, DWDM
Rate: 10G
9. CFP, CFP2 and CFP4 optical modules
40Gbit/s, 100Gbit/s
10. QSFP28 optical module
40Gbit/s, 100Gbit/s
SFF is divided into 2×5, 2×10, etc. according to its pins
In addition, there are passive optical network PON (A-PON, G-PON, GE-PON) optical modules, 40Gbs high-speed optical modules, SDH transmission modules (OC3, OC12, OC48), storage modules, such as 4G, 8G, etc.
Among them, GigacBiDi series single-fiber bidirectional optical modules use WDM technology to realize a fiber transmission of two-way information (point-to-point transmission. In particular, fiber resources are insufficient, and one fiber is required to transmit two-way signals).
GigacBiDi includes
SFP single fiber bidirectional (BiDi),
GBIC single fiber bidirectional (BiDi),
SFP + single fiber bidirectional (BiDi),
XFP single fiber bidirectional (BiDi),
SFF single fiber bidirectional (BiDi) and so on.
Application situation
Type: Single-mode optical module is suitable for long-distance transmission; multi-mode optical module is suitable for short-distance transmission.
Function: The optical module is used as a carrier for transmission between the switch and the device, which is more efficient and safer than the transceiver.
· D/T (datacom/telcom)
Data communication mainly includes computer video, data communication, etc.
Telcom mainly includes wireless voice communication and so on.
Such products are mostly used in the backbone network of optical fiber networks.
· PON: English: passive optical network
Namely: passive optical network. Such products are mainly used in access networks in optical fiber network systems. The triplex products can not only transmit optical fiber signals, but also output analog signals.
Optical modules are mainly divided into: GBIC, SFP, SFP+, XFP, SFF, CFP, etc., and optical interface types include SC and LC. However, SFP, SFP+, and XFP are now commonly used instead of GBIC. The reason is that GBIC is bulky and easily broken. The “” SFP, which is commonly used now, is small and cheap.
In 2013, the top 10 optical module vendors (in no particular order) were: Finisar America, Avago America, Oclaro America, WTD China, JDSU America, Sumitomo Japan, Hisense China, NEC Japan, Source Photonics America, NeoPhotonics America
There are 6 American companies on the list, and both quality and quantity have an absolute advantage. China and Japan each have 2 companies.
