“Single-mode Fiber Systems" and "Multi-mode Fiber Systems"

Undoubtedly, fiber optic telecommunication is an important pillar of modern communication, which has the advantages of high speed rate, large capacity, low loss, etc. Fiber optic cables and patch cords are able to accomplish tasks of long-distance and high-quality information transmission, playing a dominant role in the global telecommunication network. And as the two main ways of optic fiber communication, single-mode fiber system and multi-mode fiber system also attracted much attention.

The main content of this article is the definition, operating principle and main differences between single-mode fiber optic system and multi-mode fiber optic system, if you need, please add this passage into “my favorites” and forward to your friends so that more people can know about the professional knowledge of fiber optic system.

Definition and Operating Principle of Single-mode and Multi-mode Fiber Systems

Definition of Single-mode and Multi-mode fiber systems: in order to support different categories of applications, ISO/IEC 11801:2017 specifies five types of optical fibers, including two single-mode fiber types (OS1a & OS2) and three multi-mode fiber types (OM3, OM4, OM5).

Single-mode Fiber Systems’ Operation Principle: Single-mode fibers allow only one mode (fundamental mode) of light to propagate through them. Optical signals are transmitted in single-mode fibers by total reflection, which results in lower loss and longer transmission distances. Based on the ISO/IEC 11801:2017 standard, OS1a class fiber is usually used for indoor fiber optic cabling and OS2 class fiber is usually used for outdoor fiber optic cabling.

Multi-mode Fiber System’s Operating Principle: Multiple modes of light propagation can exist simultaneously in a multi-mode fiber. Due to the effect of mode dispersion, the transmission distance is relatively short for multi-mode optic fibers. OM3 and OM4 multi-mode fibers can be called laser-optimized multi-mode fibers, which are used to support 10 Gigabit and 10-Gigabit-above multi-mode fiber system applications, and the two types of fibers are designed with the same structure, while the bandwidths are different. OM5 multi-mode fibers can also be called wavelength-division multiplexed multi-mode fibers(i.e.WDM multi-mode fiber). Compared to OM4, the OM5 standard calls for a modal bandwidth of both 4700 Mhz/km at 850 nm and 2470 Mhz/km at 953 nm according to fiber standard.

Difference between Single-mode Fiber Optic System and Multi-mode Fiber Optic System

(i) Wavelength, Bandwidth and Transmission Distance

Applications Supported by Single-mode Fiber

Note: The maximum application (channel length) supported by single-mode fiber is defined as 2000m in the ISO/IEC 11801:2017 standard.

Applications Supported by Multi-mode Fiber

Note: The application protocols recognized by IEEE 802.3 exclude 40GE SWDM4 & 100GE SWDM4.

(ii)Transmission Rate, Application Scenarios, Cost and Expense

Single Mode Fiber(SMF) is usually applied in long-distance fiber optic communication system. Compared with multi-mode fiber, single-mode fiber has the features such as smaller core diameter, longer transmission distance, lower transmission attenuation and stable transmission performance, etc. The cost of single-mode fiber system perhaps is comparatively higher since the cost of laser device(LD) in the single-mode fiber is higher. Whereas, in the aspects of overall efficiency of long distance and big-capacity transmission such as cross-city and cross-country long-distance communication backbone network, or the core network of telecommunication carriers, or the connection between data centers or other large-capacity data transmission, single-mode fibers have irreplaceable advantages such as low-loss & long-distance characteristics.

Multi-mode fiber (MMF) is often used in short-distance and medium-distance fiber optic communication systems. Compared with single-mode fiber, multi-mode fiber has the characteristics of larger core diameter, shorter transmission distance, high transmission attenuation and large dispersion. Compared with the single-mode fiber system, multi-mode optical module’s price is much lower than that of the laser (LD) of the single-mode optical module the multi-mode optical module uses VESEL as the laser of the multi-mode optical module. So in the practice of short-distance and medium-distance fiber optic communication applications, the overall cost of the multi-mode optical fiber system is more advantageous than that of the single-mode fiber. And multi-mode fiber optic cabling system has a very wide range of applications in LAN, campus network, enterprise network and other small-scale network systems. (PS: Generally, fiber optic communication includes optical module (also called "fiber optic transceiver module") and fiber optic cabling system).

It should be noted that with the continuous development and improvement of technology, the performance of single-mode fiber and multi-mode fiber is also being optimized and improved in terms of transmission rate. However, generally speaking, single-mode fiber system and multi-mode fiber system have their own advantages and applicability in different application scenarios.

Highlights and Advantages of Zhaolong's Single-mode and Multi-mode Fiber Systems

The highlights and advantages of Zhaolong's single-mode fiber optic cabling system are as follows:

• Zhaolong’s single-mode fiber optic cabling system adopts high-precision ceramic ferrule, and advanced grinding technology and grinding equipment. The technical parameters of vertex offset, fiber height and radius of curvature(ROC) of Zhaolong single-core fiber optic connectors are in accordance with GR-326-CORE and IEC 61755 standards; Zhaolong’s multi-core fiber optic connectors adopt high-precision MPO/MTP connecting components, which are in accordance with and better than GR-1435-CORE and IEC 61754-7, with excellent  docking performance and high reliability. The product passes 100% optical performance test, with low loss, high return loss, high reliability and other excellent performances; Zhaolng’s single-mode fiber adopts selected insensitive-bending single-mode fiber which is suitable for dense fiber optic cabling application scenarios and can effectively reduce the difficulty of cabling operation and maintenance.

• Made of high-quality environment-friendly materials,  RoHS and REACH compliant.

Zhaolong OS2/OM3/OM4 fiber optic patch cords(from left to right)

Zhaolong’s multi-mode fiber optic cabling system has the following highlights and advantages:

(1) Comprehensive solution: Zhaolong’s multi-mode fiber optic cabling system provides a full set of fiber optic cabling solutions, including optic fiber wiring products with fusion splicing demands, high-density pre-terminated fiber optic wiring products, and ultra-high-density pre-terminated fiber optic wiring solutions;

(2) Time and Cost Advantage: Zhaolong’s plug and play multi-mode fiber optic cabling system adopts modular design, which can save you a lot of installation time, and also reduce your network management and maintenance costs;

(3) Customization: Zhaolong’s multi-mode fiber optic cabling system can support customization of various lengths, polarities, and numbers of cores;

Zhaolong’s Fiber Optic Cable

(4) Excellent component performance: Zhaolong multimode fiber optic cabling system selects high-performance and high-reliability connecting components, and the components’ performance meets and exceeds the international standards GR-326-CORE and GR-1435-CORE;

(5) Low loss: The connector products of Zhaolong multi-mode fiber optic cabling system have passed 100% optical testing, with 3D guarantee, and have excellent optical and mechanical properties, which are manifested as low insertion loss and low return loss in high-speed network environment, and improving the channel loss margin required for fiber optic interconnection applications between devices.

(6) Excellent system performance: fiber performance meets and exceeds IEC 60793-2-10 standard, system performance meets and exceeds ISO/IEC 11801-1 standard.