Gigalight 100G Optical Modules Passed the Connectivity Test of Multiple Cloud Service Providers

Shenzhen, China, May 19, 2018 – Gigalight announced the 100G series optical transceiver modules have passed the connectivity test of multiple cloud service providers. The Gigalight 100G series products include 100G QSFP28 SR4 multi-mode VCSEL optical modules and 100G QSFP28 CWDM4 single-mode WDM optical modules. The interconnection test covers the mainstream cloud devices of major brand equipment vendors and the optical transceiver module products of our partners.



Qualified 100G Series Optical Transceiver Modules


Gigalight has always been among the top 10 companies in the world of optical interconnects with its invention of active optical cables and deep innovation. However, Gigalight is essentially an integrated solution provider of optical transceiver modules and optical network devices. Gigalight ships a large number of 10G multimode and 10G single-mode optical modules and 40G multimode SR4 optical modules to the world. In the field of 40G single-mode optical modules, Gigalight’s main customers include global TIE1 equipment vendors. The cloud service providers have directly verified Gigalight’s 100G optical modules since the end of 2017. The successful interconnection results so far have greatly encouraged Gigalight’s confidence in deploying 100G optical modules in bulk in the cloud.


Global Data Center Infrastructure Ecosystem


Global Data Center Infrastructure Ecosystem


Gigalight has a deep optical interconnect product line. Among this product line, the multimode optical interconnect products based on the VCSEL technology applications are the traditional advantages of Gigalight, including the cost-effective and reliable 100G QSFP28 SR4 optical modules with good compatibility. The single-mode 100G series short-range optical modules were developed in 2016 and this time passed the threshold of full-brand compatibility and interoperability testing after optical design thresholds and reliability verification thresholds. Finally, they will not lose pace in the industry’s striding forward in 2018.


As a global optical interconnect design innovator, Gigalight has prepared the best 100G optical modules for industry users.


About Gigalight:

Gigalight is a global optical interconnection design innovator. We design, manufacture and supply various kinds of optical interconnect products including optical transceivers, passive optical components, active optical cables, GIGAC™ MTP/MPO cablings, and cloud programmers & checkers, etc. These products are designed for three main applications which are Data Center & Cloud Computing, Metro & Broadcast Network, and WIreless & 5G Optical Transport Network. Gigalight takes the advantages of exclusive design to provide customers with one-stop optical network devices and cost-effective products.

What is Data Center Interconnect/Interconnection?

Data Center Interconnection means the implements of Data center Interconnect (DCI) technology. With the DCI technology advances, better and cheaper options have become available and this has created a lot of confusion. This is compounded by the fact that a lot of companies are trying to enter this market because there is a lot of money to be made. This article is written to straighten out some of the confusion.

According to the different applications, there are two parts of data center interconnections. The first is intra-Data Center Interconnect (intra-DCI) which means connections within the data center. It can be within one building or between data center buildings on a campus. Connections can be a few meters up to 10km. The second is inter-Data Center Interconnect (inter-DCI) which means connections between data centers from 10km up to 80km. Of course, connections can be much longer but most of the market activity for inter-DCI is focused on 10km to 80km. Longer connections are considered Metro or Long-haul. For reference, please see the table below.

DCI Distance Fiber Type Optics Technology Optical Transceivers
intra-DCI 300m MMF NRZ/PAM4 QSFP28 SR4
500m SMF QSFP28 PSM4
2km QSFP28 CWDM4
10km QSFP28 LR4
inter-DCI 10km SMF Cohernet QSFP28 4WDM-10
20km QSFP28 4WDM-20
30km to 40km QSFP28 4WDM-40
80km to 2000km CFP2-ACO


The big bottlenecks are in the intra-DCI and therefore, the highest volume of optical transceivers are sold here generating the most revenue, however, it is low margin revenue because there is so much competition. In this space, may of the connections are less than 300m and Multi-Mode Fiber (MMF) is frequently used. MMF is thicker, and components are cheaper because the tolerances are not as tight, but the light disperses as it bounces around in the thick cable. Therefore, 300m is the limit for many types of high speed transmission that use MMF. There is a data center transceiver with a transmission distance up to 100m over OM4 MMF for example.

Gigalight 100GBASE-SR4 100m QSFP28 Optical Transceiver

100G QSFP28 SR4 for MMF up to 100m

In a data center, everything is connected to servers by routers and switches. Sometimes a data center can be one large building bigger than a football field and other times data centers are built on a campus of many buildings spanning many blocks. In the case of a campus, the fiber is brought to one hub and the connections are made there. Even if the building you want to connect to might be 200m away, the fiber runs to a hub, which can be more than 1km away, so this type of routing increases the fiber distance. Some of the distances between buildings can be 4km, requiring Single Mode Fiber (SMF), which has a much narrower core, making it more efficient, but also increasing the cost of all related components because the tolerances are tighter. Therefore, with data centers growing, so has the need for SMF as the connections get longer within the data center. With SMF you have the option to drive high bandwidth with coherent technology, and we’ll see more of this in the future. Previously coherent was only used for longer distances, but with cost reductions and greater efficiency versus other solutions, coherent is now being used for shorter reaches in the data center.

Gigalight 100GBASE-LR4 Lite 4km QSFP28 Optical Transceiver

100G QSFP28 LR4L for SMF up to 4km

500m is a new emerging market and because the distance is shorter, a new technology is emerging, and that is silicon photonics modulators. EMLs (Externally Modulated Lasers) perform modulation within the laser, but with silicon photonics, the modulator is outside the laser and it’s a good solutions for distances of 500m. In an EML, the modulator is integrated into the same chip, but is outside the laser cavity, and hence is “external”. For silicon photonics, the laser and modulator are on different chips and usually in different packages. Silicon photonics modulators are based on the CMOS manufacturing process that is high scale and low cost. A continuous wave laser with silicon photonic modulation is very good for 500m applications. EMLs are more suitable for longer reaches, such as 2-10km. Therefore, with data centers growing, so has the need for single mode fiber as the connections get longer within the data center. With SMF you have the option to drive high bandwidth with coherent technology, and we’ll see more of this in the future. Previously coherent was only used for longer distances, but with cost reductions and greater efficiency versus other solutions, coherent is now being used for shorter reaches in the data center.

100GE PSM4 2km QSFP28 Optical Transceiver

100G QSFP28 PSM4 for SMF up to 500m/2km

100GE CWDM4 2km QSFP28 Optical Transceiver

100G QSFP28 CWDM4 for SMF up to 2km

100GBASE-LR4 10km QSFP28 Optical Transceiver

100G QSFP28 LR4 for SMF up to 10km


Inter-DCI is typically between 10km and 80km, including 20km and 40km. Before we talk about data center connectivity, let’s talk about why data centers are set up the way they are and why 80km is such an important connection distance. While it is true that a data center in New York might backup to tape in a data center in Oregon, this is considered regular long-haul traffic. Some data centers are geographically situated to serve an entire continent and others are focused on a specific metro area. Currently, the throughput bottleneck is in the metro and this is where data centers and connectivity are most needed.

100GE 4WDM-20 20km QSFP28 Optical Transceiver

100G QSFP28 4WDM-20 for SMF up to 20km

100GE 4WDM-40 40km QSFP28 Optical Transceiver

100G QSFP28 4WDM-40 for SMF up to 40km

Say you have a Fortune 100 retailer and they are running thousands of transactions per second. The farther away a data center is, the more the data is secure because the data center is so far away and separate from natural disasters, but with the increased distance there are more “in flight” transactions are at risk of being lost due to latency. Therefore, for online transactions there might be a primary data center that is central to retail locations and a secondary data center that is around 80km away. It’s far enough away not to be affected by local power outages, tornadoes, etc, but close enough that there is only a few hundred milli-seconds of latency; therefore, in the worst case a small number of transactions would be at risk.

In another example of inter-DCI, as if a certain video is getting a lot of views, the video is not only kept in its central location, but copies of the video are pushed to metro data centers where access is quicker because it’s stored closer to the user, and the traffic doesn’t tie up long haul networks. Metro data centers can grow to a certain size until their sheer size becomes a liability with no additional scale advantage and thus they are broken up into clusters. Once again, to guard against natural disasters and power outages, data centers should be far away. Counterbalancing this, data centers need to have low latency communication between them, so they shouldn’t be too far away. There is a compromise and the magic distance is 80km for a secondary data center, so you’ll hear about 80km data center interconnect a lot.

It used to be that on-off keying could provide sufficient bandwidth between data centers, but now with 4K video and metro bottlenecks, coherent transmission is being used for shorter and shorter distances. Coherent is likely to take over the 10km DCI market. It has already taken over the 80km market but it might take time before coherent comes to 2km. The typical data center bottlenecks are 500m, 2km, and 80km. As coherent moves to shorter distances, this is where the confusion comes.

The optical transceiver modules that were only used within the data center are gaining reach, and they’re running up against coherent solutions that were formerly only used for long distances. Due to the increasing bandwidth and decreasing cost, coherent is being pulled closer into the data center.

The other thing to think about is installing fiber between data centers. Hopefully this is already done, because once you dig, it’s a fixed cost, so you put down as many fibers as you can. Digging just for installing fiber is extremely expensive. In France when they lay fiber, they use another economic driver. Whenever you put in train tracks, you put in fiber at the same time, even if it is not needed. It’s almost for free because they are digging anyway. Fibers are leased to data centers one at a time; therefore, data centers try to get as much bandwidth as possible onto each fiber (this is also a major theme in the industry). You might ask, why not own your own fiber? You need to have a lot of content to own your own fiber. The cost is prohibitive. In order to make the fiber network function, all the nodes need to use the same specification and this is hard. Therefore, carriers are usually the ones to install the full infrastructure.

Article Source: John Houghton, a Silicon Valley entrepreneur, technology innovator, and head of MobileCast Media.

Gigalight’s First Successful Project for the Russian ISP Market Based on GIGAC™ Cabling

Shenzhen, China, May 9, 2018 − The Gigalight's GIGAC™ MTP/MPO Cabling Portfolio has won the first big order in the Russian ISP market. In the next three years, Gigalight will provide the largest Russian Internet service provider with the GIGAC™ high-density cabling products for the data centers in major Russian cities.

Data centers are very important for modern large IT business units. As the largest Internet service provider in Russia, this client has its own data centers with the major target to optimize the network and improve the quality of the business. On the picture below, the right is the previous organization of the racks and on the left is the current installation.

Data Center Cabling Racks

The Gigalight company together with the expertise partner in Russia have solved this challenge and ensured the reliability for the current network.

Data Center Cabling Racks

Almost the full range of Gigalight optical transceivers and GIGAC™ cabling products, including GIGAC™ MTP/MPO patch cables, trunk cables, harness cables, hydra cables, GIGAC™ racks and cassettes are used in this project. They are particularly reliable and safe, and can withstand temperatures up to 70 °C. Typical uses for the cables include delivering optimal performance and data transmission for information systems.


This order follows after the years of the hard work with the Russian market. Well-known companies, public and private operators of data and communications networks are placing their trust in Gigalight’s expertise for years. Their confidence is based on our powerful cabling solutions, optical transceivers manufacturing capacity, and the tireless support we provide to our customers.

Gigalight is the world's design innovator in the optical interconnect field and this order sees it continue to build on this strong position. The company has rich experience in the development and production of optical transceivers, GIGAC™ MTP/MPO cables and passive optical components. In addition to connectivity solutions for the interconnect field, Gigalight also develops checkers and programming boards for the production lines, data centers and our global partners.

About Gigalight:

Gigalight is global optical interconnection design innovator. A series of optical interconnect products include: optical transceivers, passive optical components, active optical cables, GIGAC™ MTP/MPO cablings, and cloud programmers & checkers, 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.

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A Guide to the Interfaces of Optical Transceiver Modules

In today’s optical communications market, there are a variety of transceiver modules with various types of interfaces. Because different types of cables/connectors/adapters are required for different interfaces, we need to pay more attention when selecting the relevant assemblies. This article will give you a detailed introduction to the mainstream transceiver module interfaces on the market, so that everyone has a clearer understanding of the transceiver modules.


First of all, we use the following table to list all transceiver modules’ interfaces.


Form Factor Transmission Mode Interface Example
QSFP-DD Multiplexing Dual CS 200G QSFP-DD CWDM8
QSFP28 Parallel MPO 100G QSFP28 SR4/PSM4
QSFP28 Multiplexing Duplex LC 100G QSFP-DD LR4/CLR4/CWDM4/ER4
QSFP+ Parallel MPO 40G QSFP+ SR4/PSM4
QSFP+ Multiplexing Duplex LC 40G QSFP+ LR4
SFP28 Dual Fiber Duplex LC 25G SFP28 SR/LR
SFP28 Single Fiber Bidirectional Simplex LC 25G SFP28 BiDi
SFP+ Dual Fiber Duplex LC SFP+ 10GBASE-SR/LR
SFP+ Single Fiber Bidirectional Simplex LC/SC SFP+ BiDi
SFP+ 2-channel Bidirectional Dual LC SFP+ 2-channel BiDi
SFP+ Electrical Copper Cable RJ-45 SFP+ 10GBASE-T
SFP Dual Fiber Duplex LC SFP 1000BASE-SX/LX
SFP Single Fiber Bidirectional Simplex LC/SC SFP BiDi
SFP 2-channel Bidirectional Dual LC SFP 2-channel BiDi (CSFP)
SFP Electrical Copper Cable RJ-45 SFP 1000BASE-T
CXP Parallel MPO 120G CXP SR10
CFP Parallel MPO 100G CFP SR10
CFP Multiplexing Duplex LC 100G CFP LR4/ER4
CFP2 Parallel MPO 100G CFP SR10
CFP2 Multiplexing Duplex LC 100G CFP2 LR4/ER4
CFP4 Parallel MPO 100G CFP4 SR4
CFP4 Multiplexing Duplex LC 100G CFP4 LR4/ER4


As the table shows, although there are more than a dozen types of transceiver modules, there are only a few types of interfaces. These types of optical interfaces are LC, SC, MPO, and CS. And there are also electrical copper transceiver modules using the RJ-45 interface. Among these interfaces, the LC interface can be divided into duplex and simplex, and there are dual-simplex LC interface (such as CSFP). For BiDi optical transceivers, there are also simplex SC interface, in addition to the simplex LC. We will introduce each of these interfaces one by one, according to the transmission modes of the transceiver modules.




As we konw, a transceiver module consist of a transmiter and a receiver. This means that the transmission has two directions. For the common single-channel optical transceivers, such as SFP28, SFP+, and SFP, the transmitting terminal is connected to one optical fiber and the receiving terminal is also connected to one optical fiber. That’s why the common optical transceivers are called dual-fiber transceiver generally. The dual-fiber transceiver has a duplex LC interface connected to a duplex LC patch cable. (The XENPAK, X2, and GBIC dual-fiber transceivers, not listed in the table, have a duplex SC interface connected to a duplex SC patch cable.)


Standard Transmission Mode of Transceiver Modules


Standard Dual-Fiber Optical Transceiver Modules


The single-fiber bidirectional transmission mode is called BiDi for short. The BiDi signals in both directions are combined in a single fiber. The bidirectional transmission means that the light is directional and will not interference each other. The BiDi optical transceiver, such as BiDi SFP+ and BiDi SFP, have a simplex LC or SC interface connected to a simplex LC or SC patch cable. And for high-density BiDi transmission networks, there are 2-channel BiDi SFP+/SFP (CSFP+/CSFP) optical transceivers using dual simplex LC interface.


Single-Fiber Bidirectional Transmission Mode of Transceiver Modules


Single-Fiber BiDi Optical Transceiver Modules




For multi-channel optical transceivers, such as 4-channel QSFP+, 4-channel QSFP28, and 8-channel QSFP-DD, there are several Tx and several Rx. Some of them (such as 100G QSFP28 SR4 and 100G QSFP28 PSM4) have MPO interfaces, that is, multi-fiber pull on/off, using multiple optical fibers for the parallel transmission shown as the figure below.


Multi-Fiber Parallel Transmission Mode of Transceiver Modules


Multi-Fiber MPO Optical Transceiver Modules


There are also dual-fiber 4-channel optical transceivers using the multiplexing transmission mode, that is, multiple Tx multiplexing and Rx demultiplexing. These optical transceivers, such as 40G QSFP+ LR4 and 100G QSFP28 CWDM4, use two optical fibers for long-distance transmission, saving more optical fiber resources than using multi-core optical fibers. Like the common single-channel optical transceiver, the dual-fiber 4-channel optical transceiver also has a duplex LC interface connected to a duplex LC patch cable.




The QSFP-DD MSA specification defines an 8-channel module, cage and connector system. The cage and connector system provides backward compatibility to the 4-channel QSFP28 modules. Doubling the number of duplex optical links with the QSFP-DD specification requires a new smaller optical interconnect to fit in the same physical cage form factor. For the eight-channel QSFP-DD optical transceivers using the multiplexing transmission mode, a new type of optical interface called dual CS is used to replace the duplex LC. The dual CS interface is connected to the CS connector, a miniature single-position plug which is characterized by duo cylindrical, springloaded butting ferrule(s) of a 1.25 mm typical diameter, and a push-pull coupling mechanism. The CS connector provides the characteristics and simplicity of the duplex LC connector into a smaller footprint to allow 2 pairs of CS connectors to fit within the physical constraints of the QSFP-DD form factor.


CS connector




The RJ-45 interface is used in copper transceiver modules, such as 10G copper SFP+, 1G copper SFP and 100M copper SFP. The copper SFP+ transceivers transmit electrical signals over Category 6a or Category 7 copper cables with RJ-45 connectors, while the copper SFP transceivers transmit electrical signals over Category 5 or Category 5e copper cables with RJ-45 connectors.


RJ-45 copper SFP

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Should We Use 3rd-party Compatible Optical Transceivers?

It is no secret that most IT companies currently use or have future plans to start using 3rd-party compatible optical transceivers – because of simple fact that they are much more budgetary than Original Equipment Manufacturer (OEM) optical transceivers. However, there are still many companies that dare not use 3rd-party compatible optical transceivers.



Doubts of using OEM hardware or 3rd-party hardware are based on assumption that 3rd-party hardware will void OEM device warranty and support. Comparing some of the biggest network equipment vendors’ warranty policies (Cisco, HPE, Juniper, etc.), we can find that most of them have similar rules on using 3rd-party compatible optical transceivers. If problems are caused by 3rd-party compatible optical transceivers, then warranty support will be refused until optical transceivers are changed to OEM ones. In the mean while, if defect to vendor’s equipment is caused by 3rd-party compatible optical transceiver and it is proved by vendor, then warranty can also be voided. Then, should we still use 3rd-party compatible optical transceivers? Let’s talk about the difference between 3rd-party transceivers and OEM transceivers first.



In fact, there is no real difference between 3rd-party transceivers and OEM transceivers. The 3rd-party transceivers ensures the same working and quality standards as OEM transceivers, because they are manufactured and assembled in the same factories where OEM branded ones are. And largest part of optical transceivers is manufactured mostly at the Aisan countries such as China, Malaysia, and Thailand etc. Optical transceivers are standardized by Multi-Source Agreement (MSA) specifications. This means everyone can manufacture and supply optical transceivers. As a result there is absolutely no difference in hardware for official branded transceiver and reliable 3rd-party compatible optical transceiver, as much as four or ten times cost difference. The performance is the same because all manufacturers follow the same rules and standards.


Optical transceivers in general are based on very basic technology. They are destined to be like that because they are mostly driven by laser which is active component and has fixed longevity. When laser gets out of shape, optical transceiver is easily exchangeable to new one. As a result, there is no reason for OEM transceivers to be more costly compared to similar 3rd-party compatible transceivers. As well they don’t have any much options damaging device where they are used. In our personal experience, our company have delivered tens of thousands optical transceivers in previous years, and we have never met a technical problem when optical transceiver does some hardware based damage to device where it is used. 3rd-party compatible optical transceivers can be as reliable as official OEM ones.


Now that there is no real difference between OEM transceivers and 3rd-party transceivers, then why network equipment vendors have such strict warranty policies? That is because network equipment manufacturers have to make money. They will use all available resources to sell more of their production. So they make warranty policies which psychologically affects their customers, making them think that there will be problems (warranty void) if they use other vendor equipment’s products (such as the 3rd-party transceivers) in their OEM devices.


In the legislatio of the United States, there is a law which prohibits warranty void only because your customer uses other vendor’s equipment which is analogue to original vendors equipment. Voiding of a warranty in this situation would be violating what is defined in the Magnuson-Moss Warranty Act of 1975 (15 United States Code section 2302(c)) as a “Tie-In Sales” provision.


Of course the OEM switch manufacturer’s warranty would not cover any 3rd-party transceiver deployed in their devices. Sometimes OEM vendors try to exaggerate this as if it is an odd, difficult or exceptional issue. The truth is a typical network is composed of many devices from many different manufacturers, with each device supported by its manufacturer’s warranty.

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Gigalight 3rd-party Compatible 100G QSFP28 Optical Transceivers: