State Road Shu small classroom 100G optical module introduced species, you need to look this!

The optical communication industry standards related mechanism mainly from IEEE, ITU and Multi Source Agreement MSA Industry Alliance, 100G plurality of standard module, the customer can choose the most cost-effective type of modules according to different application scenarios. Multiple applications within 300m short multimode fiber, VCSEL lasers, 500m 40km-transmission using single-mode optical fiber, DFB laser or EML.
Compared with 2.5G, 10G or 40G WDM transmission system, 100G optical transmission using digital coherent receiver by phase diversity and polarization diversity to map all of the optical properties of the optical signal to the electrical domain, the use of sophisticated digital signal processing in the electrical domain implementation of the polarization demultiplexing, channel impairments equalization compensation, timing recovery, carrier phase estimation, and symbol estimation linear decoding. In the transmission of light while achieving 100G, 100G optical module has undergone a series of major technological change, wherein the phase modulator comprises a polarization multiplexing technology and digital coherent receiving technology Super third generation error correction coding technology, thereby meeting the user when both into demand.
Classification optical module
100G optical module package main mainstream CXP, CFP, CFP2, CFP4, CFP8, QSFP28. With the development in recent years, CFP products shipments decreased, QSFP28 packaged in a smaller size, lower power consumption has been fully won, but just the rise of 200G, 400G package also most of the use QSFP-DD package. Most companies have QSFP28 optical module package of 100G products to market.

CXP optical module
a transmission rate of up to 12 CXP optical module 10Gbps, hot-swappable, "C" in hexadecimal 12 Representative Roman number "X" represents each channel has a transmission rate of 10Gbps. "P" refers to the hot-swappable pluggable device. CXP optical module market mainly for high-speed computers, CFP optical module complements the Ethernet data center. Technically, CFP optical module and a multimode optical fiber applied with the short-distance data transmission. Since the multimode fiber market requires a high density panel, so that the size has not been truly optimized multimode fiber on the market.
CXP optical module length 45mm, width 27mm, is larger than the size CFP optical module or an XFP optical module, thus providing a higher density of the network interface. In addition, the CXP optical module is designated by the trade associations copper broadband wireless connector system may support 12 suitable for 100GbE, 3 10G is applied to 40GbE uplink transmission channel 12 or 10G Ethernet or Fiber Channel radio 12 wideband signal QDR link transmission.

CFP / CFP2 / CFP4 optical module
CFP Multi-Source Agreement (MSA) defines the requirements applicable to hot-pluggable optical module 40G and 100G transmission network, comprising next-generation high-speed Ethernet (40GbE and 100GbE). CFP optical module supports multiple rates, transmission protocol and the link length is required in the single mode and multimode fiber, including standard IEEE 802.3ba all media contained in the relevant (PMD) interfaces, 100G network Hu three PMD: 100GBASE-SR10 can transmit 100m, 100GBASE-LR4 can transmit 10KM, 100GBASE-ER4 can transmit 40KM.
CFP optical module SFP optical module is designed on the basis of the interface (the SFP), larger support 100Gbps data transmission. CFP optical module electrical interface 10 is used in each direction (the RX, the TX) 10Gbps transmission channel, and therefore support 10 Huzhuan of 4 * 25Gbps and 10Gbps. CFP optical module 100G may support a single signal, OTU4, or a 40G signal, OTU3 or STM-256 / OC-768.
Although 100G CFP optical module may implement data applications, via its large size, can not meet the demand for high-density data center, in this case, CFP-MSA committee defines two other forms: CFP2 and CFP4 optical module.

QSFP28 optical module
QSFP28 QSFP optical module and the optical modules, with the same design. For QSFP28, each channel can send and receive data up to 28Gbps. CFP4 compared with an optical module, QSFP28 CFP4 optical module smaller in size than optical module. QSFP28 optical module having advantages over CFP4 density optical module, power consumption generally does not exceed 3.5W work, while the other power module is typically between light 6W to 24W. Seen in this light, other than the 100G optical module power consumption is much lower.

CFP2 / CFP4 / QSFP28 size comparison chart:

the optical module test
test, should be noted that the wavelength and shape of the transmitter output waveform, and a receiver jitter tolerance and bandwidth, the test transmitter, note:
a transmitter portion
1, with to test the quality of the transmitter input signal must be good enough. In addition, the electrical measurements must be confirmed by mass measurement and jitter measured by the eye. Eye measurements common method is to check the transmitter output waveform, because the eye contains a wealth of information, it can reflect the overall performance of the transmitter.

2, the output optical signal transmitter must eye diagram, and amplitude modulation light extinction ratio of the optical quality indicators measured.

Receiver portion
different from the transmitter is a test, when the test receiver, the quality of the optical signal must be sufficiently difference, therefore, there must be created a worst eye optical pressure signal representative of one, the worst this optical signal It must be calibrated by measuring the jitter and the optical power measurement.
Need to test an electronic output signal of the receiver, this test there are three main types:

1, eye diagram, so to ensure eye "eyes" in the open state, the eye diagram is generally realized by the depth error outspoken
2 , jitter, jitter test different types
3, tracking and jitter tolerance test where the internal clock recovery circuit can tracking jitter.

Optical test module is a complex task, but also to ensure its good performance indispensable step. Eye measurements As a measuring method, a widely used, effective light emitter test module.
With the development of technology, 100G network applications from more and more common, 100G optical modules are becoming more cost-effective. 100G QSFP28 optical communication module supply path state, 100G CFP / CFP2 / CFP4 optical modules are able to meet the appropriate standard, wide selectivity, high stability, high cost, also provide a comprehensive network solutions that help users build a low cost cost-effective network system.