An Overview on 100G QSFP28 4WDM and 100G QSFP28 ER4 Lite

There are two new QSFP28 optical transceiver products appeared in the optical module market: 100G QSFP28 4WDM 40km optical transceiver and 100G QSFP28 ER4 Lite optical transceiver in last month. However, many people don’t know too much about the 100G QSFP28 4WDM 40km optical transceiver and 100G QSFP28 ER4 Lite optical transceiver. Here Gigalight is going to have a brief introduction about the two products to help you have a better understanding and make the right choice when purchasing them. 

Introduction on 100G QSFP28 4WDM:

4WDM MSA ( defines our familiar CWDM4 and 4WDM products with different distances and wavelengths (2km/10km/20km/40km). It’s shown as follows.

2km and 10km use CWDM wavelength; 20km and 40km use LAN WDM wavelength.

Because of the difference in the size of the CWDM and LAN WDM wavelengths, the wavelength-transmitting TOSA for LAN WDM must be carried with a TEC (Thermo Electric Cooler). As the stable wavelength drifts with temperature, TEC consumes an extra 0.5W of power, so the overall power consumption of optical transceivers with LAN WDM wavelengths will be higher than that of CWDM optical transceivers.

The BER requirement of module product defined by 4WDM MSA is better than 5E-5, because the system or switching equipment has the FEC front-end error correction function to meet the overall link bit error rate requirements. FEC has pros and cons, it increases packet delay and overall power consumption of the device while enabling. For example, when multiple devices in the network architecture enable FEC, the delay of FEC is cumulative, which is fatal for a dedicated network requiring high real-time performance, like financial trading system and so on.

Introduction on 100G QSFP28 ER4 Lite:

IEEE 802.3ba defines that the 100GBASE-LR4 / 100GBASE-ER4 series has a BER requirement of better than 1E-12 w / o FEC for optical modules. Since the receiving sensitivity of 100GBASE-ER4 is not satisfied with the existing APD technology, the SOA size is too large for the QSFP28 series; many optical module companies in the industry defined a non-standard 100GBASE-ER4 Lite with QSFP28 package that the largest transmission distance is up to 30km without FEC.

The receiving sensitivity of 100GBASE-ER4 Lite 30km has no clear definition in IEEE802.3ba. At the current level of 100G APD ROSA, the average of OMA Sensitivity is around -17dbm (BER 1E-12@25.78125Gbps). The description of the100GBASE-ER4 Lite products in the industry is defined as 30km w/o FEC, 40km with FEC. During product development, I deliberately tested 40km OTU 27.95Gbps 70-degree long-distance running error in a laboratory environment. It meets the 1E-12 BER w / o FEC. The receiver sensitivity data cannot meet the requirements of protocol 100GBASE-ER4. The running fiber can meet the 40km application.

Difference between 100G QSFP28 4WDM and 100G QSFP28 ER4 Lite

The 100G QSFP28 ER4 Lite supports dual rate 100GE and OTU4 applications, while the 100G QSFP28 4WDM 40km only supports 100GE applications.


With the development of device packaging technology, there is a plan to develop a small SOA + PIN integrated ROSA in the industry. When the technology is mature, the QSFP28 products meeting the 100GBASE-ER4 standard will also be released. And now Gigalight has released the latest 100G QSFP28 4WDM 40KM optical transceiver and 100G QSFP28 ER4 Lite 40KM optical transceiver. For more product details, you can directly visit its official website.


What Is Optical Communication and Its Advantages

Optical communication is a communication way with optical wave as carrier. There are two methods to increase optical bandwidth: the first is to increase the single channel transmission rate of optical fiber; the second is to increase the number of wavelengths transmitted in a single fiber (WDM). Here Gigalight is going to introduce what optical communication and its main advantages to help you know the field better.

What Is Optical Communication?

The basic optical fiber communication system consists of data source, optical transmitter, optical channel and optical receiver. The data source includes all the signal sources, and they are the signals obtained by the source code of voice, image and data. The optical transmitter and modulator are responsible for converting the signal into an optical signal that is suitable for transmission on the optical fiber. The optical wave window include: 0.85, 1.31 and 1.55. Optical channels include the most basic optical fiber, and the relay amplifier EDFA, etc. The optical receiver receives the optical signal and extracts the information from it, then converts it into electrical signals, and finally obtains the corresponding voice, image, data and other information.

The computers and mobile phones around us send messages via electrical signals « 0 and 1 ». Optical communication consists of a « transmitter » that converts electrical signals into optical signals, a “receiver” that converts optical signals into electrical signals, and « optical fibers » that transmit optics.

Three Main Advantages of Optical Communication

1. Long Transmission Distance, Save Energy

Suppose you want to transmit 10Gb of information in one second (10 billion signals). If you use electrical communication, you need to adjust the signal every 100 meters. In contrast, using optical communication requires an interval of more than 100 kilometers. The fewer times the signal is adjusted, the fewer machines will be used, thus saving energy.

For example, when you phone or chat online now with your foreign friends, you will feel there is no difference with the domestic conversation, without lag in sound. In an era of electrical communication, one can transmit at a short distance and transmit less information, and international communication is mainly transmitted through satellite as relay. However, with optical communication, one can transmit at a long distance and transmit more information. Therefore, by using fiber-optic cables laid on the seafloor, it is possible to communicate with overseas. Electrical waves have the same speed as optical waves. However, because the transmission path is longer by satellite, the signal arrives slower. The submarine cable is much shorter, so the signal will be faster.

2. Transmit Massive Amount of Information at One Time

Using optical communication, a large number of users can receive the required information at the same time (movies or news, etc.). In one second, electrical communication can transmit only 10Gb of information (10 billion 0 and 1 signals). In contrast, optical communication can transmit information of up to 1Tb (1 trillion 0 and 1 signals).

3. Fast Communication Speed

Electrical communication can cause errors in electrical noise, resulting in decreased communication speed. However, optical communication is not affected by noise, so it can transmit signals quickly.


The ultimate goal of the future transmission network is to construct an all-optical network, which is to fully realize « optical fiber transmission instead of copper wire transmission » in the access network, metropolitan area network and backbone network. The backbone network and the metropolitan area network have basically realized the all-optical network. In the today that information society develops faster and faster, optical communication will inevitably facilitate the further advancement of network.

About Gigalight:

Gigalight is a design innovator in global optical interconnect field. A series of optical interconnect products include: optical transceivers, passive optical components, active optical cables, GIGAC MTP/MPO cablings, cloud programmers & checkers, and etc. Three applications are mainly covered: Data Center & Cloud Computing, MAN & Broadcast Video, and Mobile Network & 5G Optical Transmission. Gigalight takes advantage of its exclusive design to provide clients with one-stop optical network devices and cost-effective products.

Ethernet vs. Wi-Fi: Which One to Choose

Now we are living in a networking world. Using Ethernet or Wi-Fi can help us to get better wireless network experience. However, we often feel confused while choosing between Wi-Fi and Ethernet. Which one shall I choose? What factors shall be taken into consideration before selecting one of them? Both of the two connections have their own advantages and disadvantages. And these pros and cons are based on some different factors, like speed, security, reliability, latency, etc. Here Gigalight is going to discuss all of the factors in detail below.

Firstly, we need to make it clear that the definition of Ethernet and Wi-Fi before comparing them.

What Is Ethernet and What Is Wi-Fi?

Ethernet is a way of connecting computers together in a local area network or LAN. It has been the most widely used method of linking computers together in LANs since the 1990s. Ethernet is created by Xerox, and jointly developed into the one by Xerox, Intel and DEC. It adopts the CSMA/CD access control method and is conformed to IEEE802.3.

Wi-Fi is the technology that allows a PC, laptop, mobile phone, or tablet device to connect at high speed to the internet without the need of physical wired connection. Wi-Fi uses radio signals to transmit information between your Wi-Fi enabled devices, like your mobile phone, and the internet, allowing the device to receive information from the web in the same way that a radio or mobile phone receives sound.

What’s the Difference between Ethernet and Wi-Fi?

When discussing Ethernet vs. Wi-Fi, there are many differences that can be considered which form the deciding factors in choosing one over another. Some users prefer speed, some users prefer reliability, some users consider security, and some users always like the latest technology. Therefore, the following part will introduce the main differences between Ethernet and Wi-Fi that affect people’s choices.

1. Speed

Wi-Fi has become pretty fast over the years with standards such as 802.11ac and 802.11n being able to give us speeds of 866.7 Mb/s and 150 Mb/s, respectively. That is pretty fast and meets most of our needs, especially when it comes to using the internet.

What about the speed of an Ethernet cable? There are standards for Ethernet cables like cat-5, cat-5e, cat-6 cables etc. Theoretically, a wired Ethernet connection can offer up to 10 Gb/s if you have cat-6 cable. However, the most common cat-5e cable supports up to 1 Gb/s. Ethernet is faster, this is undoubtedly true. If you’re using multiple devices, such as a server where all your data is stored or for LAN gaming, you might consider switching to an Ethernet cable.

2. Reliability

Talking about reliability, Wi-Fi is less reliable of the two. Because a number of things can affect a wireless signal, from other wireless devices to physical objects and walls. This interference can cause dropped signals, higher latency and even lower speeds at times. While it doesn’t matter much when all you need to do is stream content over the internet but for any other purposes, You can minimize this by ensuring your router is placed in the optimum position in your home, but it’s unlikely that you will ever achieve the same levels of stable performance that you will get from Ethernet.

3. Security

When comparing Ethernet vs. Wi-Fi, security is another big factor that needs to be considered. The data on an Ethernet network can only be accessed by devices physically attached to the network. These devices, including the laptop at one end and router at the other, need firewalls to protect them, but there’s way the data itself can be intercepted on the network.

With Wi-Fi, the data is in the air. If you’re using an open network (such as in a coffee shop) then all the data you send and receive can be intercepted, including personal information and login details. That is to say, it is easier to hack into a Wi-Fi network than getting a physical access to the physical Ethernet cable.


Of course there are other factors considering when you want to choose Ethernet or Wi-Fi, like latency, interference, and so on. Generally speaking, Ethernet offers the advantages of better speed, lower latency, and more reliable connections. Wi-Fi offers the advantage of convenience and being good enough for most uses. So, you can choose one of them according to your actual use.

About Gigalight:

Gigalight is a design innovator in global optical interconnect field. A series of optical interconnect products include: optical transceivers, passive optical components, active optical cables, GIGAC™ MTP/MPO cablings, cloud programmers & checkers, etc. Three applications are mainly covered: Data Center & Cloud Computing, MAN & Broadcast Video, and Wireless & 5G. Gigalight takes advantage of its exclusive design to provide clients with one-stop optical network devices and cost-effective products.

Why 100G Optical Transceivers Are So Popular in 5G Fronthaul

Today we are going to talk about a segmentation closely related to the 5G theme – 100G optical transceivers. Recently, there has been a new landmark theme, which is « 100G optical transceiver », what are the reasons?

What Are 100G Optical Transceivers?

1. The first explain is that the 100G « G » refers to the optical signal transmission rate of units, rather than the 5G « G » (Generation, 5th generation mobile communications).

2. Optical transceiver is one of optical devices to achieve high-speed conversion between optical signals. It includes the optical receiver, optical transmitter, laser, detector and other functional modules.

3. According to the packaging types (CFP / XFP / SFP / QSFP, etc.), the transmission rate (155Mbps ~ 200Gbps), optical link (CWDM / DWDM / PSM), mode (Single-mode / Multi-mode), Plug-in/out mode (Fixed / Hot-pluggable) and other categories, optical transceivers have various kinds of categories. If considering the operating temperature range, whether the number of self-diagnostic functions and performance classification elements, optical transceiver categories are more.

4. The basic structure of an optical transceiver includes a laser (TOSA) + driving circuit, a detector (ROSA) + receiving circuit, a multiplexer (MUX), a demultiplexer (DEMUX), an interface, an auxiliary circuit and a housing.

5. Driven by technological upgrading and cost reduction, the optical transceiver continues to be « high speed, miniaturization and integration. » 100G optical transceivers use 25G laser chip technology. According to the different packaging methods, 100G optical transceivers are CFP / CFP2 / CFP4, CXP and QSFP28. QSFP28 is a new generation of 100G optical transceiver packaging, and has now become the mainstream packaging of optical transceivers.

6. 100G optical transceivers have different models and standards. Generally speaking, the transmission rate of optical signals is much higher than that of low-rate 10G and 25G products. Now they have become the star products in large-scale data centers and telecom markets.

Why Are 100G Optical Transceivers So Popular?

1. From the Market Segmentation Point of View

 The optical transceiver market can be subdivided into Telecom, Datacom and Access markets. Access market generally use 10G and below the low-speed optical transceiver. North American data center market is undergoing 40G to 100G upgrading, the current high-speed optical transceiver is the main growth point. After 5G construction started, the telecommunications market for high-speed optical transceiver demand will be larger than the data center market.

2. The Relationship between Optical Transceivers and 5G

With the evolution of 5G technology, based on the requirement of higher base station density, there will be greater new demand and market space for high-rate optical transceivers. At present, LTE base stations of 4G mainly use 10G optical transceivers, and 25G / 100G optical transceivers are the preferred solutions of the front 5G optical transmission modules in the future.

(1) At present, the market demand for digital communications is growing rapidly: the demand for high-end optical transceivers in Internet data centers is accelerating, especially in overseas digital communications markets. In the data center server and switch, a large number of connections are using optical communication technology; data center network has become the driving force for the growth of optical transceivers. With the construction of large-scale data centers and the outbreak of traffic, the demand for optical transceivers in the data center has been shifted from 10G / 25G to 40G / 100G and 100G has become the mainstream since 2017. 

(2) The rapid increase of optical transceiver industry profit in 2016 was mainly due to the sharp increase in the demand for 100G optical transceiver in North American cloud computing center. The demand for optical transceiver increased sharply, and 100G optical transceiver in the market was in short supply. It is estimated that the global 100G optical transceiver shipments in 2017 will reach 200-300 million.

(3) Telecommunication Network Market (Three Major Carrier Capital Expenditure Items): Optical communication is the cornerstone of 5G and the demand of 5G for high-rate optical transceivers increases. At present, LTE base stations of 4G mainly use 10G optical transceivers, and 25G / 100G optical transceivers are the preferred solutions of the 5G fronthaul optical transceivers in the future.

Each base station needs 12 25G / 100G optical transceivers: one base station has one BBU and connects to three RRUs, and each BBU uses three pairs of six optical transceivers, each pair uses two pairs of RRUs, for a total of 12 optical transceivers. Theoretically, due to the characteristics such as high frequency, high density and high connection of 5G, the domestic future needs to build nearly 10 million base stations, that is, the demand of hundreds of millions of optical transceivers, and the number of base stations in North America is 10 million, The demand for high-speed optical transceivers brought by 5G construction will be even greater. At present, there are many kinds of mature 100G optical transceivers in the market, like 100G QSFP28 CWDM4, 100G QSFP28 PSM4 and 100G CFP / CFP2 / CFP4 optical modules provided by Gigalight. They cover the mainstream form factors: CFP / CFP2 / CFP4 / QSFP28 and can be used for a variety of optical network bearer demand.

Why You Should Choose 100G QSFP28 Optical Transceivers

The continuous and rapid development of the Internet as well as the desire of people for higher speed optical networks facilitated the vigorous development of the entire optical communications industry and strongly promoted the independent R & D and innovation in many core technologies including optoelectronic devices technologies. 100g optical transceiver is regarded as the product of this big data era.

The first generation of 100G optical modules is CFP optical module with very large volume, then CFP2 and CFP4 optical modules appears. CFP4 optical module is the latest generation of 100G optical module, the width is only 1/4 of CFP optical module. Its package size is not same as the QSFP + optical module. The QSFP28 optical module has a smaller package size than the CFP4 optical module, which means the QSFP28 optical module has a higher port density on the switch. The following are several 100G QSFP28 series optical modules:

Main Types of QSFP28 Optical Transceivers

100G QSFP28 LR4 is a 100Gb/s transceiver module designed for optical communication applications compliant to 100GBASE-LR4 of the IEEE P802.3ba standard. 

100G QSFP28 SR4 is a four-channel, pluggable, parallel, fiber-optic QSFP+ SR4 optical transceiver module for 100/40 Gigabit Ethernet, Infiniband DDR/EDR and 32GFC applications.

100G QSFP28 PSM4 is a four-channel, pluggable, parallel, fiber-optic QSFP28 PSM4 optical transceiver module for 100/40 Gigabit Ethernet and Infiniband DDR/EDR Applications.

100G QSFP28 CWDM4 is a 100Gb/s transceiver module which is designed for optical communication applications compliant with the QSFP MSA, CWDM4 MSA and portions of IEEE P802.3bm standard.

Of course, QSFP28 series also includes 100G QSFP28 active optical cables; these products have played an important role in the development of 100G.

Advantages of 100G QSFP28 Optical Transceivers

1. Power Consumption

The power consumption of QSFP28 typically is no more than 3.5W, while the power consumption of other 100G optical modules typically is between 6W and 24W. From this, the power consumption of QSFP28 optical modules is much lower power than other 100G optical modules.

2. Cost

Now the data center is mainly 10G network architecture, in which the interconnection solutions are mainly 10GBASE-SR optical module and duplex LC multimode fiber jumper. If the existing 10G network architecture based on the direct is upgraded to 40 / 100G network, it will save a lot of time and cost. Therefore, one of the major interconnection trends in data centers is to upgrade from 10G networks to 40 / 100G networks without changing existing duplex multimode infrastructure. In this case, the MPO / MTP branchable cable is undoubtedly the ideal solution for a 10G upgrade to 40 / 100G.

3. Bandwidth

The QSFP28 uses the advanced 100G transport technology to provide the data center with a connection between the chassis switch and the core network, providing up to 150% greater panel bandwidth density than the 40G QSFP solution

Optical Module Test

When using optical modules, test performance is an essential step. Optical module is composed of transmitter and receiver, so when we test, it is generally divided into four steps, which mainly includes the transmitter and receiver test.

First, the transmitter part:

When testing, pay attention to the wavelength and shape of the transmitter output waveform, as well as the receiver’s jitter tolerance and bandwidth. When testing the transmitter, note the following:

1. The quality of the input signal used to test the transmitter must be good enough. In addition, the quality of the electrical measurements must also be confirmed by jitter and eye measurements. Eye diagram measurements are a common way to check the transmitter’s output waveform because the eye diagram contains a wealth of information that reflects the overall performance of the transmitter.

2.The output optical signal of the transmitter must be measured by the optical quality index such as eye pattern test, optical modulation amplitude and extinction ratio.

Second, the receiver part:

Unlike test transmitters, the quality of the optical signal must be sufficiently poor when testing the receiver that a light pressure eye pattern representing the worst signal must be created. This worst case optical signal must pass through jitter measurements and light Power test to calibrate.

1. Eye pattern test, this will ensure that the eye « eye » is open. Eye diagram testing is usually done at the depth of the bit error rate;

2. Jitter test to test different types of jitter;

3. Jitter Tracking and Tolerance, testing the internal clock recovery circuit to track the jitter.

All in all, testing light modules is a complex undertaking, but it is also an indispensable step in ensuring good performance. Eye diagram measurement is a widely used measurement method that can effectively test the transmitter of an optical module. The optical module receiver test is more complex, but also requires more testing methods. 

What Are CWDM Optical Modules and Their Differences

CWDM optical module adopts CWDM technology, which can combine optical signals with different wavelengths through an external wavelength division multiplexer. It saves fiber resources by transmitting through one optical fiber. At the same time, the receiving end needs to use the wave-demultiplexer to decompose the complex optical signal. In addition, CWDM optical modules can be plugged into switch or router SFP ports. This article will describe in detail what CWDM optical modules are and what are the differences between CWDM optical modules and other modules.

The Main Form Factors and Type of CWDM Optical Modules

There are three types of CWDM optical module form factors: SFP, SFP + and XFP. The transmission distance is generally as follows: 40KM, 80KM, 100KM, and 120KM.

CWDM optical modules can be divided into: CWDM SFP optical module, CWDM GBIC optical module, CWDM SFP + optical module, CWDM XFP optical module, CWDM X2 optical module, CWDMXENPAK optical module and CWDM LX-4 optical module.

The Differences between CWDM Optical Modules and Ordinary Optical Modules

CWDM optical modules are passive modules that do not emit laser. They generally use optical planar waveguide (PLC) technology; just a beam of light is divided into several beams of light. The ordinary optical modules belong to the photoelectric conversion device, which are active optical modules. Each module has two ports for receiving and transmitting, and the launch port inside is a laser.

CWDM Optical Modules VS DWDM Optical Modules: Which One to Choose?

The principle of DWDM optical modules is similar to CWDM optical modules, except that DWDM optical module are optical modules for dense wavelength division multiplexing, and has 40 common channels to choose from.

CWDM optical modules are widely used in schools, data centers, FTTH (Fiber to the Home), 1G and 2G Fiber Channel, metro Ethernet, security and protection systems and other fields.

DWDM optical modules are mainly used in long-distance optical synchronous digital transmission networks, such as Ethernet / Fiber Channel with 200km links and 80km links.

From a cost point of view, CWDM optical modules are cheaper than DWDM optical modules. CWDM optical modules provide a convenient and cost-effective solution for using Gigabit Ethernet and Fiber Channel.

DWDM optical modules, on the other hand, typically use denser channel spacing and are used for large optical networks over longer distances. If you want long-distance SFP modules, DWDM optical modules are the ideal choice.

The Differences between CWDM4 and PSM4 

CWDM4 optical module transmission rate is 103.1Gbp, mainly used in computing, high frequency trading and other fields. Its cost is significantly higher than QSFP28 PSM4.

1. The optical transmitter: PSM4 needs four integrated silicon photonic modulator and a distributed feedback laser, and CWDM4 needs four CWDM direct modulation laser;

2. The connector: PSM4 needs a MPO connector with 8 fibers, CWDM4 needs duplex LC connector;

3. The optical fiber: PSM4 is a ribbon SMF (8 core), CWDM4 is a duplex SMF;

4. The transmission distance: PSM4 is 500 meters, CWDM4 is 2000 meters

5. The four wavelength of CWDM multiplexer: PSM4 does not need, but CWDM4 needs.

In Conclusion 

CWDM optical modules are multi-rate optical modules with 20-40km, 40-80km and 80-120km transmission distances. The optical modules of different wavelengths are marked with different colors to better meet customer requirements.

What Are the Impacts of High or Low Temperature on Optical Transceivers?

The working temperature of optical transceivers affects all the parameters of optical transceivers. If the ambient temperature of the optical transceiver changes, the operating current of the optical transceiver will vary with temperature. At the same time, the parameters of the optical transceivers change, which affects the normal transmission of optical transceivers. Today, we mainly talk about the causes of too high or too low temperature on optical transceivers and its impact.

What Is the Normal Temperature of Optical transceivers?

Because the type and brand of the optical transceiver are complicated, the temperature of modules corresponding to different optical transceiver temperature levels are different and the temperature specifications defined by the supplier are different, whether the temperature of optical transceivers is abnormal or not needs to be considered according to these factors. Before we use the optical transceiver, it is best to check the vendor’s definition of the temperature profile of the optical transceiver so as to reduce the number of problems caused by abnormal optical transceiver temperature.

Optical transceiver temperature mainly includes three levels: commercial grade, extended grade, industrial grade. The following is a detailed description of these three temperatures:

Temperature Grade



Temperature Range

Commercial temperature range


0 ~ + 70 ℃

Extended temperature range


-20 ~ 85 ℃


Industrial temperature range


-40 ~ 85 ℃


Three Reasons That Affect the Temperature of Optical Transceivers

1. The Poor Quality and Workmanship

If you use the optical transceivers with poor quality and workmanship, then the phenomenon of abnormal temperature of the optical transceivers is more common. Because the function of such optical transceivers is instable, heat dissipation is also relatively poor. In order to reduce the temperature anomaly and unnecessary discard, we advise to use the optical transceivers with better function, quality and workmanship.

2. The Harsh Application Environment

Optical transceiver operating environment is in the data center, computer room or interchanger. If the optical transceivers are used in other environments, the change of the ambient temperature will inevitably change the temperature of the optical transceiver, thereby affecting its optical power and optical sensitivity. If the application environment of optical transceivers is harsh, then we advise to select the optical transceivers with industrial temperature or extended temperature.

3. The Use of Second-hand Optical Transceivers

The temperature of new optical transceivers is usually at 0-70 ° C and many second-hand optical transceivers are inaccessible. And the second-hand optical transceivers cannot operate normally in high-temperature or low-temperature conditions. Therefore, we advocate the use of new optical transceivers.

What Are the Impacts of High or Low Temperature on Optical transceivers?

If the optical transceiver temperature is too high or too low, it will affect the function of the optical transceiver and make the communication data appear faulty. The optical transceivers will alarm if its temperature isn’t in the normal range. If the optical transceivers are in a bad situation, interchangers will send data continuously. The optical transceivers will not send / receive data from the beginning until it is recovered to normal operation.

1. The Impact of Too High Temperature on Optical Transceivers: 

If the operating temperature of optical transceivers is too high, the optical power of optical transceivers will become larger and the receiving signal will be faulty, and even the optical transceiver will be burned. As a result, the optical transceivers cannot work normally. In this case, DDM function should be added. You can select temperature control system for real-time monitoring and compensation to ensure that the optical transceiver extinction ratio and luminous power stable, to ensure the normal operation of the optical communication system.

2. The Impact of Too Low Temperature on Optical Transceivers:

Generally speaking, as long as optical transceivers are not exposed to the harsh environment below 0℃, the temperature will not be too low. It is better not to use the optical transceiver in the condition of too low temperature, as this may cause the function of the optical transceiver to be unstable.

How about the Temperature of Gigalight’s Optical Transceivers?

As one of the most top-rated optical transceiver vendors in China, Gigalight complies with the temperature grade standard that the industry requires, and will meet the customer demand for temperature. In addition, all optical transceivers will undergo a high and low temperature burn-in test prior to shipping to test the temperature to ensure the quality of the products.


Something about 100G Optical Transceivers That You Want to Know


With the development of science and technology, the application of optical communications products in real life is becoming more and more widespread. The demand for network technology is also getting higher and higher. Therefore, 100G optical transceivers are gradually appearing on the market. The development of 5G and Data Center further make the 100G optical transceivers become the mainstream of the optical transceiver market gradually. Perhaps you have had a certain understanding of 100G optical transceivers, but if we analysis 100G optical transceivers from another point of view, you will find something different.

Development Background of 100G Optical Transceivers

For the earliest developed 100G optical transceiver, the form factor is CFP, developed in 2010. At that time, IEEE launched 100G optical transceiver SR10, LR4 and ER4 three standards, separately aiming at the 100m, 10Km and 40Km transmission. Followed by that, the IEEE standard added the new 100G SR4 project, but in 2013 did not reach consensus and vacancies. By 2016, the 100G optical transceivers used by various data centers were mostly the 25Gbps Serdes program, and the 100G optical transceivers that use the 50Gbps Serdes planned slowly appeared.

The Facing Problems for 100G Optical Transceivers

1. Channel Distance: The DWDM system supporting the 50GHz wavelength distance is very extensive. The 100G optical transceiver needs to meet the condition of supporting the 50GHz wavelength distance, therefore, the pattern of high spectral power should be used.

2. OSNR (optical signal-to-noise ratio): Under the same pattern, 100G optical transceivers requires10dB higher than 10G optical transceivers and 4dB higher than 40G optical transceivers. Therefore, a low OSNR tolerance code and high coding gain FEC algorithm are needed.

3. CD Margin: Under the same conditions, 100G optical transceiver dispersion tolerance only needs 1/100 of 10G optical transceiver, accounting for 16/100 of 40G optical transceiver. Therefore, 100G optical transceivers can use dispersion compensation technology, in the electric field or the optical domain compensation to complete the dispersion compensation for each wavelength.

4. PMD Tolerance: Under the same conditions, PMD (polarization mode dispersion) tolerance of 100G optical transceiver is 1/10 of 10G optical transceivers, accounting for 4/10 of 40G optical transceiver, so you need to choose coherent reception plus digital signal processing.

5. Nonlinear Effects: Compared with 10G / 40G optical transceiver, the nonlinear effects of 100G optical transceivers are messier.

The Types and Advantages of 100G Optical Transceivers

The main form factors of 100G optical transceiver include: CFP, CFP2, CFP4 and QSFP28. To compare their advantages, the main factor to consider is the costs and power consumption for Data Centers.

1. CFP optical transceiver supports all C-band wavelengths tunable and can complete the link detection, which use a common optical dual-binary modulation format ODB, convenient layout, power consumption is less than 24W.

2. The volume of CFP2 optical transceiver is one-half of CFP, its integration is 2 times CFP. It can complete the wide dynamic input range based on SOA to achieve stable admission sensitivity, support a full CFP optical transceiver, its low power consumption is lower than 9W.

3. The volume of CFP4 optical transceiver is one-half of CFP2, its integration is twice that of CFP2, front panel port density is also doubled compared with CFP2. CFP4 optical transceiver follows the MSA protocol, support the same rate as CFP/CFP2. Its transmission power increases significantly, but the power consumption drops significantly, only about half of the original, the system cost is lower than the CFP2. In addition, CFP4 optical transceiver uses 4 * 25 forms, through the 4 * 25G channel, complete 100G transmission. The transmission power is higher with higher stability.

4. The form factor of QSFP28 optical transceiver is smaller than the CFP4 optical transceiver. QSFP28 optical transceiver power consumption is generally not more than 3.5W, the use of QSFP28 optical transceiver can directly upgrade from 25G to 100G not through 40G, and therefore the cost is lower.




The Largest Transmission Distance




Fiber Types









(CFP4 doesn’t support SR10)









Dual LC






Dual LC






Dual LC































Dual LC












Learning the contents of the 100G light module, above, do you have any further information? From the development trend, QSFP28 optical transceiver and CFP series optical transceiver are 100G network hot solutions, and the use of CXP will be less and less. Gigalight, as a veteran optical transceiver manufacturer with professional technology, advanced R & D capability and stable manufacturing capability, not only has many popular 100G optical transceiver products, like 100G QSFP28 CWDM4, 100G QSFP28 PSM4, CFP2 100G LR4, and etc. but also will release more new 100G optical transceivers in the first quarter of this year. More information about 100G optical transceivers, please visit the official website.


100G CFP and CFP MSA?

100G optical module is an important part of the high-speed optical transmission network. Some people say that the optical module has the status of a vice commander in the entire communication system. The rapid development of optical fiber network, people in the communication industry are obvious to al. 100G optical module is regarded as the mainstay of the 5G network, the market has to tell all of us with the truth that the optical module has changed the original market structure.


Speaking of 100G optical module standards and types, the market mainstream models are mainly CFP / CFP2 / CFP4 and QSFP28. As an early appeared optical module, CFP is now gradually replaced by QSFP28. But the basic principle of the optical module has not changed, and we still can learn it to understand the 100G optical module. Today we will talk about what CFP is and the 100G CFP multi-source agreement (MSA).

What Is CFP Optical Transceiver?

Designed primarily for the 100G market, the CFP optical transceiver is specifically sized for long range interfaces and single-mode fiber applications. It is 120mm long and 86mm wide. It is the same length as a 10G XENPAK optical transceiver but twice as wide. At the same time this optical transceiver has good thermal performance, making it in the process of using small power consumption.

Gigalight can provide several kinds of mainstream CFP optical transceivers: CFP 100GBASE-SR10, CFP 100GBASE-LR4, CFP2 100GBASE-SR10, CFP2 100GBASE-LR4, and 100GBASE-SR4 CFP4. Besides, it will release the latest 100G CFP2 ER4/100G CFP ER4 in January, 2018. These optical transceivers can achieve different transmission distances by connecting with different types of optical fibers.



Transmission Distance





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 The Origin and Application of 100G CFP Optical Module MSA

CFP MSA is the acronym for 100G Form factor Pluggable Multi-Source Agremment. In March 2009, the multi-source agreement was announced for the CFP module by Finisar, Opnext and Sumitomo to define high-speed Ethernet for 40G and 100G applications and support the next generation. In June 2010, CFP MSA ushers in a new member, AVGO, and released a multi-source agreement for a new version (Rev 1.4).

The CFP MSA introduces the block diagram of the CFP module. The DMUX and MUX in the optical part perform the optical demultiplexing and multiplexing. The WDM (wavelength division multiplexing) technology multiplexes the optical signals of multiple wavelengths onto a single-mode optical fiber for transmission. The module can work at ITU WDM wavelength. The module adopts the single fiber connection mode, which can save 2 × (N-1) optical fibers. In practical applications, the transmission distance of the single-mode optical fibers can reach more than 10km. In the schematic, N represents the number of optical channel, M represents the number of circuit channels. Generally, M and N are not equal. The electrical interface rate of the module is 10 Gbit / s. To implement 100 Gbps rate transmission, 10 electrical interfaces are required to support this. The number of electrical interfaces is 10 for the 100GBASE-LR4 and 100GBASE-ER4, and four for the 40GBASE-FR.

100G CFP Optical Module Hardware Definition

The CFP module has up to 148 pins, distributed at the bottom and top of the module’s electrical interface. The host computer can read the module control and status information through the electrical signal interface, which contains 6 control pins, 5 hardware alarm pins (including RX_LOS) and 8 MDIO management interface pins. Optical interface part may have SC, LC, and MPO connector form.

After accessing to the host, CFP optical modules can do the orderly timing switch according to the monitoring status. The timing diagram below is for the module in each steady-state and transient state signal associated with the flag switch.

CFP module operating temperature is not specified: 0 ℃ to 70 ℃. The module manufacturers need to test the performance of these modules in the two temperature conditions and have been to ensure that modules in the whole temperature range can reach the target requirements. The corresponding host also needs to provide the necessary cooling system to ensure that the module operates in this temperature range.

CFP SMA also defines the module size, weight, plug-in strength and so on, as well as the mainframe connected to the module of the various mechanical and electrical structures are detailed design. If you have any question or suggestion, welcome to visit our official website: Gigalight.

Technology for 100G CFP/CFP2 LR4 Optical Transceiver

The form factors of 100G CFP optical modules can be divided into CFP/CFP2/CFP4, and they can be divided into 100GBASE-SR10, 100GBASE-LR4, and 100GBASE-ER4 according to the transmission distance. All optical module transmission distance is decided by the optical output signal OSNR tolerance and chromatic dispersion tolerance decision. Generally speaking, it is determined by the laser and its drive performance.

At present, there are two types of optical modulation methods for implementing CFP 100GBASE-LR4 transmission in the mainstream market. One is a Direct Modulation Laser Modulation (DML) mode, that is, a direct modulation laser. And another one is an Electlro -Modulation Modulation (EML) mode, that is, modulation laser.

The following post will briefly introduce some key technical points of using the TEC circuit and EML modulation mode to realize the 100G CFP / CFP2 LR4 optical transceivers.

1. TEC Circuit

EML lasers need to work at a certain wavelength, the temperature jump will lead to a temperature drift effect, resulting in wavelength instability, drifting, so the stable working conditions of the laser is a relatively stable operating temperature (steady wavelength) This requires that we have to provide a high-precision TEC circuit, that is, a semiconductor refrigerator. The TEC is actually a PN junction made of two semiconductors of different materials. When a direct current passes through the PN junction, electrons and gaps in the two materials The hole produces an endothermic or exothermic effect during movement across the PN junction, effecting a cooling or heating laser effect, and TEC heating or cooling can be controlled by changing the current direction and size.

A high-precision op amp compares the target temperature we set with the temperature fed back by the thermistor, and the error voltage is amplified by a high-gain amplifier while compensating for the network’s contribution to the hot and cold ends of the laser The phase delay is compensated to drive the H-bridge output to control the size and direction of the TEC current. When the temperature drops below our target temperature, the H-bridge will reduce the TEC current or change the direction of the TEC current for cooling. Conversely, the final control loop Road will reach a dynamic equilibrium, the temperature will stabilize. Among them, the compensation circuit is the most critical part of the TEC temperature control circuit, that is PID proportional integral differential adjustment compensation network, which determines the TEC controller response speed and regulation accuracy.

2. EAM Regulation

EML lasers are essentially integrated devices for EAM (Electroabsorption Modulator) and LD (DFB lasers). The key core is the EML chip, which is the core of an electro-absorption modulated laser based on the Stark Effect (QCSE) design. The DML laser modulates the light intensity by directly controlling the laser current, which always works in an unstable state and is easily influenced by the outside world. In contrast, the EML laser mainly controls the optical signal by controlling the EAM, the light source will be more stable, and the transmission Relatively speaking, the characteristics and transmission effects will be better, especially in high frequency modulation and long distance.

In application, the LD pin injects a constant current to the laser to make the laser emit light, and the EAM changes the ratio of the laser light to obtain different intensity of light. The development of Ethernet technology has gone through a number of development stages from low speed to high speed.

The rate of development from 1M, 10M, 100M and 1G to 10G and 100G has led to more demand for it to evolve to a higher rate. I believe there will be new technologies have emerged to meet the growing demand for optical modules.