Demystifying 800G Transceiver: Types, Applications, and FAQs

Posted on Jan 15, 2024 by

As the demand for faster data transmission continues to surge, 800G transceiver has gained significant attention due to its high bandwidth, fast transmission rates, exceptional performance, high density, and future compatibility. In this article, we will provide an overview of the various types of 800G optical modules, discuss their applications, and address some FAQs to help you make a better choice when selecting 800G transceivers.

Types of 800G Transceiver

800G = 8 x 100G = 4 x 200G. Thus, according to the single-channel rate, 800G transceivers can be broadly classified into two categories: single-channel 100G and 200G. The figure below displays the matching architectures. Single-channel 100G optical modules can be implemented relatively quickly, while 200G optical modules have higher requirements for optical devices and require a gearbox for conversion. This article mainly introduces single-channel 100G modules.

800G = 8 x 100G = 4 x 200G

Single-Mode 800G Transceivers

The 800G single-mode optical transceiver is suitable for long-distance optical fiber transmission and can cover a wider network range.

800G DR8, 800G PSM8 & 800G 2xDR4

These three standards share similar internal architectures, featuring 8 Tx and 8 Rx, with a single-channel rate of 100 Gbps, and requiring 16 optical fibers.

800G DR8 optical module uses 100G PAM4 and 8-channel single-mode parallel technology, and the transmission distance through single-mode optical fiber can reach up to 500m, which is typically used in data centers, 800G-800G, 800G-400G, and 800G-100G interconnections. FS 800G QSFP-DD DR8 delivers exceptional performance for 800GBASE Ethernet applications, offering throughput of up to 800 Gigabits per second over eight pairs of single-mode fibers (SMF) with MPO-16 APC connectors, extending up to 500 meters. Fully compliant with IEEE P802.3ck, IEEE 802.3cu, and QSFP-DD MSA standards, this transceiver ensures seamless compatibility and reliable operation.

800G PSM8 utilizes CWDM technology with 8 optical channels, each delivering 100Gbps, supporting 100m transmission distance, making it ideal for long-distance transmission and fiber resource sharing.


800G-PSM8/DR8 Transceiver Architecture

800G 2DR4 refers to 2x “400G-DR4” interfaces. It has 2x MPO-12 connectors, enabling 2 physically distinct 400G-DR4 links from each 800G transceiver without the need for optical breakout cables. As shown in the figure below, it can be connected to 400G DR4 transceivers and supports a transmission distance of 500m, which facilitates data center upgrades.

Dual MPO-12


800G 2FR4/2LR4/FR4/FR8

800G FR and LR in these designations stand for Fixed Reach and Long Reach, for fixed and longer transmission distances, respectively.

800G 2xFR4 and 800G 2xLR4 are two additional standards with similar internal structures. They consist of 4 wavelengths operating at a single-channel rate of 100 Gbps. By employing Mux, the number of required optical fibers is reduced to 4, as shown in the figure below. These standards serve as upgrades to 400G FR4 and LR4 transceivers. They utilize CWDM4 wavelengths at 1271/1291/1311/1331nm. 800G 2xFR4 supports a transmission distance of 2km, while 800G 2xLR4 supports a transmission distance of 10km. The optical interface for these standards employs dual CS or dual duplex LC interfaces. They are both suitable for 800G Ethernet, breakout 2x 400G FR4/LR4, data centers, and cloud networks.

FS provides 800G 2xFR4 and 800G 2xLR4 modules in OSFP packages. FS 800G 2FR4 optical transceiver Module is designed for 800GBASE Ethernet throughput up to 2km over single-mode fiber (SMF) with duplex LC connectors. FS 800G 2LR4 transceiver supports up to 10km link lengths over single-mode fiber (SMF) via dual LC connectors. Both products have undergone rigorous testing and have excellent performance.

800G 2xFR4 and 800G 2xLR4

800G FR4 follows a scheme that utilizes four wavelengths and PAM4 technology, operating at a single-channel rate of 200 Gbps and requiring two optical fibers, as shown in the figure below. It supports a transmission distance of 2km and is generally used in data center interconnection, high-performance computing, storage networks, etc.

800G FR4

Lastly, 800G FR8 employs eight wavelengths, each running at a speed of 100 Gbps, as shown in the figure below. It requires two optical fibers and supports a transmission distance of 2km. Besides, 800G FR8 can provide higher transmission capacity. Common applications include wide-area networking, data center interconnection, etc.

800G FR8

Multimode 800G Transceivers

There are primarily two standards for 800G optical transceivers used in multimode applications when the transmission distance is under 100 meters.

800G SR8

The 800G SR8 transceiver adopts the VCSEL technology with a wavelength of 850nm and a single-channel rate of 100Gbps PAM4. It necessitates the use of 16 optical fibers. This can be regarded as an enhanced version of the 400G SR4, featuring twice the number of channels. The transceiver employs either an MPO16 or a Dual MPO-12 optical interface, as depicted in the diagram provided. 800G SR8 optical modules are generally used for 800G Ethernet, data center links, or 800G-800G interconnection.

800G SR8

800G SR4.2

This scheme employs two wavelengths, 850nm and 910nm, enabling bidirectional transmission over a single fiber, commonly known as bi-directional transmission. The module incorporates a DeMux component to separate the two wavelengths. With a single-channel rate of 100 Gbps PAM4, it requires a total of 8 optical fibers, which is half the amount needed for SR8.

800G SR4.2

Unleashing Potential: Applications of 800G Transceiver

In the realm of high-performance networking, the evolution of 800G transceivers has ushered in a new era of possibilities.

Data Center Connectivity

Data Center Interconnectivity is one of the primary domains where the prowess of 800G optical modules shines. With InfiniBand, these modules facilitate seamless communication between data centers, powering the backbone of modern interconnected infrastructures.

High-Performance Computing

In the arena of High-Performance Computing, where processing demands are ceaselessly escalating, the efficiency of 800G transceives becomes a game-changer. The modules ensure rapid data transfer, reducing latency, and optimizing overall system performance.

5G and Communication Networks

The surge of 5G and Communication Networks demands not only speed but also reliability. Enter the 800G QSFP and QSFP-dd transceivers, engineered to meet the demands of next-gen communication networks. Their advanced capabilities bolster the 5G architecture, ensuring a robust and responsive network infrastructure.

FAQs about 800G Optical Transceivers

Q1: What is the difference between 800G QSFP-DD and 800G OSFP for 800G optical modules?

A1: QSFP-DD (Quad Small Form Factor Pluggable Double Density) and OSFP (Octal Small Form Factor Pluggable) are two different optical module packaging types used to support high-speed optical communications. QSFP-DD is smaller and suitable for high-density port layout. In addition, the power consumption of OSFP is slightly higher than that of QSFP-DD. And QSFP-DD is fully compatible with QSFP56, QSFP28, and QSFP+, while OSFP is not. For more information, please refer to 800G Transceiver Overview: QSFP-DD and OSFP Packages.

Q2: Can the OSFP interface module be inserted into the QSFP-DD interface?

A2: No. Since QSFP-DD and OSFP interface types are different, their physical sizes and connection methods are also different, so they cannot be plugged into each other.

Q3: Can an OSFP at one end of an 800G link interoperate with a QSFP-DD at the other?

A3: Yes. The OSFP and QSFP-DD denote the module's physical form factor. The OSFP and QSFP-DD modules will interoperate with each other if the Ethernet media types are the same.

Q4: What are the advantages of upgrading to 800G technology?

A4: Moving to 800G technology offers several benefits for network infrastructure and data-intensive applications:

  1. Increased Bandwidth: 800G technology offers a significant increase in bandwidth, enabling faster and more efficient data transmission, meeting the growing demand for high-speed data transfer across various industries.

  2. Higher Data Rates: With 800G technology, data rates of up to 800Gbps can be achieved, enabling faster data processing, reduced latency, and improved overall network performance.

  3. Future-Proofing: Adopting 800G technology allows organizations to future-proof their network infrastructure, ensuring compatibility with upcoming technologies and applications.

Q5: What 800G transceivers are available from FS?

A5: The 800G modules provided by FS are shown in the table below

800G transceivers
Single Mode
QDD800-PLR8-B1 OSFP800-PLR8-B1

Q6: What are the speed and modulation formats used by 800G OSFP/QSFP-DD modules?

A6: All 800G optical modules utilize 8x electrical lanes in each direction (8 transmit lanes and 8 receive lanes), each with 100G PAM4 data rate, enabling an aggregate bandwidth of 800Gbps per module, and 8 optical waves modulated per lane.


As a key component of the next generation of high-speed optical communications, 800G optical modules are available in various types to meet different application needs. An in-depth understanding of the types, application fields, and answers to common questions about 800G transceivers will help promote the development of data transmission technology. By mastering this advanced technology, we can better adapt to the challenges and opportunities of the digital age.

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