Research on Automotive Optical Fiber Communication: Introduction of Optical Fiber in Vehicles Accelerates, with Priority Deployment in High-Speed Communication Link (10+Gbps) Scenarios

Automotive optical fiber communication refers to a communication technology that takes "light waves" as the information carrier and optical fibers as the transmission medium, transmits data through optical signals in optical fibers, and realizes information transmission through electrical/optical and optical/electrical mutual conversion, thereby achieving high-speed, real-time, anti-interference data interconnection between various in-vehicle electronic control units (ECUs), sensors, display devices, computing units and other components.

A complete automotive optical fiber communication system mainly includes automotive optical modules, automotive-grade optical fiber harnesses, and automotive optical fiber connectors.
Automotive optical modules: Realize the conversion between optical and electrical signals, e.g., the transmitting end converts electrical signals into optical signals and the receiving end converts optical signals into electrical signals.
Automotive-grade optical fiber harnesses: Serve as the physical transmission medium to carry optical signals, featuring light weight, anti-electromagnetic interference, and low transmission loss.
Automotive optical fiber connectors: Used to connect optical fiber harnesses with optical modules, device interfaces, etc., and need to meet automotive-grade requirements such as vibration resistance, temperature resistance, and low insertion loss.

With the evolution of automotive E/E architecture from the distributed to the central computing + zonal control, the demand for in-vehicle communication has exploded. In particular, as vehicle intelligence develops, the number of sensors and display screens deployed in vehicles surges, resolution requirements get higher, and L3/L4 autonomous driving requiring data transmission reliability and low latency has ever higher requirements for automotive data transmission.      

Using copper cable harnesses is expected to fail to meet future vehicles’ layout requirements for high speed and low weight. Traditional bus communication technologies adopt copper cable harnesses. When the transmission rate exceeds 10Gbps, thicker copper wires are required to meet the rate requirements. However, in vehicle layout environment, the thickening of copper wires will lead to an increase in overall vehicle weight and vehicle costs. In addition, copper wires need to increase the electrical signal frequency to improve the communication bandwidth, and higher electrical signal frequency is more sensitive to electromagnetic interference, resulting in higher electromagnetic shielding costs for copper cable harnesses. 

To address above problems, the use of optical fibers is attracting attention in the automotive field. Optical fibers have the advantages of high speed, high reliability, low loss and anti-electromagnetic interference, and their transmission rate is much higher than that of traditional copper wires or coaxial cables, which can meet communication needs of automotive systems for large data volume and high real-time performance. Therefore, optical fiber is undoubtedly the optimal choice at the in-vehicle 10Gbps bandwidth watershed. The IEEE 802.3cz standard also provides a feasibility support for introduction of optical fiber in vehicles. 

Automotive Optical Fiber Communication: International Standard Optical Fiber Ethernet Has Completed Real-Vehicle Verification, While Chinese Automotive PON Is in the Standard Formulation Stage

Technical Routes for Automotive Optical Communication: Optical Fiber Ethernet & Automotive PON

There are two main technical routes for automotive optical fiber communication: one is a high-speed automotive communication method based on optical fiber Ethernet, complying with the IEEE 802.3cz protocol; the other is automotive PON solution.
Optical fiber Ethernet: Only supports point-to-point communication; switches are required to establish communication between multiple nodes.
PON (Passive Optical Network): Supports point-to-multipoint communication, with core lying in downlink distribution or uplink convergence.

The core of automotive optical fiber Ethernet communication is to use multimode silica optical fibers as physical transmission medium to carry standard Ethernet data frames. It is not an isolated new technology. The entire system architecture integrates traditional Ethernet with automotive-specific protocols, is compatible with the upper-layer protocols (MAC/TSN, etc.) of traditional automotive Ethernet, and adopts traditional Ethernet frame format and MAC layer protocol, with data transmission based on MAC addressing, suitable for scenarios compatible with existing automotive Ethernet ecosystem.

The advantage of optical fiber Ethernet lies in its complete Ethernet-based ecosystem, based on Ethernet switches with good integration, and compliance with the IEEE 802.3cz protocol. Ethernet switches adopt optical interfaces and highly integrated optoelectronic devices in VCSEL + PHY + PD + BGA package. However, the problem is that the P2P architecture fails to efficiently utilize optical transmission.

In terms of suppliers of automotive optical fiber Ethernet communication, leading suppliers include domestic and foreign optical communication enterprises such as KD Semiconductor, Hinge Technology, and Zhongji InnoLight, which have proposed many products and solutions. At present, most products and solutions are in the real-vehicle verification stage, and mass production is expected to be realized in 2026. 

Take Zhongji InnoLight as an example: In March 2025, ReinOCS, a subsidiary of Zhongji InnoLight, released the world's first automotive optical transmission module and solution based on the PCIe 4.0 protocol, achieving an ultra-high-speed transmission of 25Gbps using optical fiber media, with a signal attenuation rate of less than 0.1dB/km and a 100-fold improvement in anti-electromagnetic interference capability. It completely solves performance constraints of traditional electrical transmission solutions, and breaks through the signal attenuation and bandwidth bottlenecks of copper cables with optical fibers as the medium.

The automotive optical transmission module based on PCIe 4.0 combines advantages of high-speed interface protocols and optical fiber transmission technologies:
Ultra-high speed and low latency: Optical fiber transmission supports the full-speed operation of PCIe 4.0, meeting real-time transmission needs of automotive systems for massive data, and achieving extremely low signal attenuation in long-distance transmission, providing key guarantees for real-time scenarios such as assisted driving, intelligent connectivity, and intelligent cockpits.
Space-optimized deployment: The PCIe 4.0 optical transmission system allows OEMs to deploy key hardware such as central computing units, sensors, and high-compute chips in various areas of vehicle body according to the optimal spatial layout, and build a collaborative transmission network through PCIe optical transmission.
Uncompromising anti-interference: Optical signals are naturally immune to electromagnetic interference, performing stably in complex electromagnetic environment of vehicles, avoiding signal distortion or loss of traditional copper cables caused by EMI, and ensuring the communication security of key systems.

Based on Zhongji InnoLight's PCIe 4.0 automotive optical transmission module, Joyson Electronics exhibited a joint automotive optical communication solution with Zhongji InnoLight, which has been production-ready. Relying on advantages of anti-interference, microsecond-level low latency and large bandwidth of optical communication, the solution supports high-speed data transmission such as DP, MIPI and PCIe, and can build a high-speed optical fiber ring network between the central domain and zone controllers. Core applications include optical transmission of 8-megapixel and 17-megapixel high-definition cameras (transmission over 100 meters) and lossless transmission of 4K@120Hz displays, meeting the needs of high-level autonomous driving and multi-screen cockpits.

Automotive PON technology is led by Chinese communication industry manufacturers, which need to study automotive PON technology adapted to the vehicle environment by drawing on mature PON technology in telecom access networks, focusing on solving the low-latency and high-reliability PON communication protocol and link layer control mechanism. At present, V-PON and TSN/TS-PON are mainly promoted in China.
V-PON: A PON technology custom-developed for in-vehicle communication needs of intelligent connected vehicles, optimized for in-vehicle traffic patterns and topological structures, aiming to realize the transformation of in-vehicle communication from "narrowband communication + copper cable harnesses" to "broadband communication + optical fiber harnesses". 
TSN-PON/TS-PON: A deep integration of Time-Sensitive Network (TSN) and Passive Optical Network (PON), whose core is to introduce and implement the TSN protocol family (clock synchronization 802.1AS, time-aware shaping 802.1Qbv, etc.) on the traditional PON architecture, thus endowing the PON with microsecond-level deterministic transmission capability. 

Advantage of PON is to realize the P2MP network architecture based on passive optical splitters, making full use of the characteristics of optical transmission; however, the key is the absence of automotive optical transmission PON protocols, and automotive PON supply chain needs to be reconstructed, such as passive optical splitter PLC chips with high isolation and low return loss, and automotive-grade optoelectronic devices such as LD, optical receiving and TIA with high temperature resistance, high responsivity and high speed.

In terms of suppliers of automotive PON communication, due to the lack of relevant standard protocols, automotive PON supply chain needs to be reconstructed. At present, only a few suppliers such as Poncan Semiconductor, FiberHome Telecommunication and Hengtong Optic-Electric have proposed automotive PON products and solutions.

FiberHome Telecommunication's V-PON solution: In November 2025, FiberHome Telecommunication officially released the V-PON solution for intelligent vehicles. The solution introduces PON technology widely used in the Fiber To The Home (FTTH), with telecom central office equipment as the central control node, connecting display screens, cameras and other terminals through optical fibers to form a point-to-multipoint transmission architecture. At present, the solution has completed a 40,000-kilometer road test on models such as Dongfeng Commercial Vehicles, marking the entry of optical communication system into the practical application stage in specific models.

Hengtong Optic-Electric's TSN-PON solution: In October 2025, Hengtong Optic-Electric successfully developed China's first 10G TSN-PON-based automotive all-optical demonstration and verification system, which innovatively introduced "data center-level" optical communication technology into automotive scenario. The main products include: photoelectric composite cables and connectors, photoelectric composite optical splitters, OLT modules, cockpit or intelligent driving parts, ONU modules supporting cameras, and ONU units for connecting Ethernet devices, completing the full-scenario transmission verification covering 8MP camera + 32- channel lidar, 12MP camera + 32-channel lidar and 20MP camera + 192- channel lidar.

Standardization Process of Automotive Optical Fiber Communication: Standards Available for Automotive Optical Ethernet, but Unavailable for Automotive PON

Automotive optical fiber communication technology is mainly used to replace in-vehicle copper cable transmission in high-speed communication links. At present, the main technologies used for high-speed link transmission such as in-vehicle video streams and backbone networks include SerDes, automotive Ethernet, and PON. Among them, SerDes and Ethernet have automotive standards, but there is no automotive standard for PON now. 

In terms of the standardization construction of automotive optical fiber communication, the international community is mainly promoting the formulation of relevant standards around optical fiber Ethernet (IEEE 802.3cz) and silica optical fiber communication (ISO 24581); in China, more emphasis is placed on innovation in PON technology, and institutions such as the Shenzhen Automotive Research Institute of Beijing Institute of Technology take the lead in organizing the formulation of relevant standards.

In March 2023, the IEEE Standards Association released the automotive optical fiber Ethernet technical standard IEEE 802.3cz-2023 (Multi-Gigabit ASE-AU), which defines a new Ethernet physical layer specification for the application of optical fiber Ethernet in automotive field, providing multi-gigabit functions through multimode optical fibers and offering theoretical support for "optical fiber on board". The standard specifies the physical layer specifications and management parameters at data rates of 2.5GBASE-AU, 5GBASE-AU, 10GBASE-AU, 25GBASE-AU and 50GBASE-AU over glass optical fibers in the automotive environment.

Automotive PON standards are currently unavailable. It is necessary to carry out technological innovation, overcome relevant core technologies and form V-PON standard specifications on the basis of existing PON technologies in response to challenges brought by in-vehicle communication needs and special working environments. 

Automotive Optical Fiber Communication Deployment Scenarios: Priority Deployment in High-Speed Communication Link (>10Gbps) Scenarios

Automotive optical fiber communication has a wide range of application scenarios in automobiles, mainly covering five core scenarios: high-speed interconnection of multiple sensors, data backbone network of central computing architecture, high-definition large-screen display of intelligent cockpits, interconnection of zone controllers, and V2X and cloud interaction.

Market demand is the core driving force for technological deployment. Although automotive optical fiber communication has a wide range of application scenarios, limited by factors such as standard unification, cost and automotive-grade verification, there are not many scenarios that can be deployed in the short term. It is expected that automotive optical fiber communication will be gradually deployed in specific scenarios such as high-bandwidth autonomous driving sensor links, video stream links of 8K ultra-high-definition display screens, and high-speed interconnection between domain controllers/central computing in the future.

Scenario 1: High-Speed Video Stream Links - Fiber Optic Cameras and Fiber Optic Displays

On intelligent driving perception side, with the advancement of L3/L4 autonomous driving, multiple high-definition cameras, lidars and other devices are required as the core of visual perception, and the improvement of their resolution and frame rate directly drives the surge in bandwidth demand. At present, mainstream automotive cameras are upgrading from 8 megapixels to 12, 15 and even 17 megapixels. Taking an 8MP camera as an example, the data volume of one 8MP camera is about 4~5Gbps (YUV422, 30fps); calculated by configuring a vehicle with 10-13 cameras, the total data volume will exceed 50Gbps. In the future, if 17MP cameras are adopted, the bandwidth demand of a vehicle may exceed 100Gbps. Traditional copper cables have become increasingly difficult to meet the video transmission bandwidth demand of high-definition cameras.   

Optical fiber communication, with its transmission rate of tens to hundreds of Gb per second, makes it possible to process such massive data. Its transmission latency is as low as the microsecond level, which is crucial for autonomous driving systems that need to make real-time responses. At present, manufacturers such as KD Semiconductor, Zhongji InnoLight, Hinge Technology and Leopard Imaging have launched solutions for fiber optic cameras.

Zhongji InnoLight's fiber optic camera solution: ReinOCS, a subsidiary of Zhongji InnoLight, and Autolink jointly launched an optical fusion camera solution, which proposed a problem-solving idea of a "modular platform": decoupling optical transmission module of the camera from front-end Sensor acquisition module. This means that OEMs can flexibly select lenses and Sensors from different suppliers, and only need to mount ReinOCS's optical module at the back end to realize lossless backhaul of Raw Data. This "plug-and-play" flexibility, combined with natural anti-interference characteristics of optical transmission, often brings more attractive implicit engineering value (such as shortening the development cycle and simplifying the harness topology) to vehicle engineers plagued by signal debugging than explicit hardware parameters.

On intelligent cockpit display side, the resolution of automotive display screens is upgrading from 2K to 4K and evolving towards 8K. The 8K integrated "ultralong screen" spanning the driver and co-pilot seats is becoming a standard configuration for high-end models. Coupled with the increase in the size of display screens, it has spawned a demand for high-speed connection solutions with a rate higher than 10Gbps. If traditional copper wire SerDes solution is used, to support such high resolution and refresh rate, two or even more cables are often required for parallel transmission, with long harness lengths, a large number of connectors and very complex harness integration. In addition, the transmission of high-speed data in copper cables also makes the electromagnetic compatibility (EMC) problem more prominent, and the overall design and maintenance difficulty of the cockpit continue to increase.

Therefore, the adoption of optical communication is more reasonable in such scenarios. Building an intelligent cockpit communication network with optical fibers can provide a high-bandwidth and stable data transmission channel to meet the needs of future upgrade and expansion; at the same time, it can bring advantages in weight and cost, which is very suitable for meeting high-performance communication network needs of intelligent cockpits.

Automotive fiber optic displays transmit video signals through optical fibers instead of traditional SerDes harnesses to drive large screens or display devices inside the vehicle, aiming to solve the challenges of high-bandwidth, long-distance and anti-interference transmission brought by high-resolution and large-size screens. In essence, the display signal of the screen is converted into an optical signal through an electro-optical conversion module, transmitted to the screen end via an optical fiber, and then converted back into an electrical signal for display.

With the popularization of 8K integrated long screens in intelligent cockpits, fiber optic displays are moving from technological pre-research to a critical node of practical deployment. At present, they are mainly in the stage of demonstration application and small-scale pre-research, with prototypes displayed at exhibitions such as CES 2026, but large-scale mass production still takes time.
 
Zhongji InnoLight's fiber optic display solution: The fiber optic display solution jointly built by Zhongji InnoLight’s ReinOCS and Autolink, is built based on the DP 1.4 protocol (supporting DP 2.1 in the future), and a single module can easily support a bandwidth of 40G. This means that the originally complex "multi-line parallel transmission" can be simplified to "one optical fiber to solve everything", which not only saves wiring space but also solves the problem of signal attenuation in long-distance transmission.

Scenario 2: Automotive Backbone Network – Optical Fiber Backbone Network

The introduction of automotive optical fiber communication is closely related to the evolution of vehicle EEA. Considering the data transmission needs of L3 and above autonomous driving and 8K automotive display screens, as well as the large-scale data transmission migration and software algorithm interaction between the central and zone controllers to meet in-vehicle functional safety requirements, 10G+Gbps high-speed communication technology will become the data backbone link in the future zonal architecture. However, automotive communication architecture based on copper cable harnesses has been difficult to adapt to the development needs of the new generation of centralized E/E architectures in terms of high-bandwidth (10Gpbs+) data transmission and low electromagnetic interference. Relying on advantages of large bandwidth, high-speed transmission capability, low transmission loss, anti-electromagnetic interference and lightweighting, optical fiber communication has become one of the important underlying technical directions supporting high-compute E/E architecture.  

At present, the industry has proposed a variety of automotive network architecture solutions based on optical fibers, whose core idea is to build a backbone communication network with optical fibers. In the short term, the industry mainstream will adopt the "optical fiber backbone + copper cable branch" photoelectric hybrid architecture, that is, optical fiber communication is used for in-vehicle high-bandwidth backbone links, CAN/LIN buses are retained for low-speed control scenarios in the domain, and copper cable Ethernet is still used for medium-speed data transmission, achieving a balance among performance, cost and reliability.

Take Autolink's photoelectric fusion architecture as an example: In January 2026, Autolink and ReinOCS, jointly released the Deep Fusion EEA, which consists of three parts: a central computing platform based on Qualcomm 8797, zone controllers based on AMD Versal AI Edge Gen 2, and a high-speed optical communication backbone network based on optical transmission PCIe communication technology. The central platform provides high-compute AI and flexible scheduling, the zone controller ensures functional convergence and fast execution, and high-speed optical communication breaks through the bottleneck of traditional harnesses to support higher-density sensing and data flow transmission.

In Deep Fusion EEA, the high-speed optical communication solution is provided by ReinOCS, showing competitive underlying technical capabilities:
Full-scenario adaptation capability: Supports lossless transmission of 8K@60Hz ultra-high-definition video, meets the data interaction needs of intelligent cockpit multi-screen interaction and autonomous driving high-resolution sensors (such as lidar, high-definition cameras), with a maximum transmission distance of up to 100 meters, covering the connection of multi-area devices of the vehicle.
Extreme environmental adaptability: Adopts a lightweight design and anti-electromagnetic interference technology, and can operate stably in an extreme vehicle environment of -40℃ to 85℃, solving the problem of signal attenuation of traditional copper cable transmission in complex electromagnetic environments.
Special optical and structural design: Both modules and harnesses can withstand high acceleration impact and full-band continuous vibration in automotive scenarios, fully complying with the reliability standards of automotive harnesses and connections. Even in complex use environments such as frequent vehicle start & stop and bumpy road conditions, it can ensure the stability and continuity of data transmission.
Architecture-level scalability: Adopts a modular interface design, which can seamlessly adapt to multi-sensor fusion needs of future high-level autonomous driving (L4 and above), providing OEMs with a flexible solution of "upgradable hardware and iterable software" and reducing long-term upgrade cost of vehicle electronic architecture.