Comparison Between MMF and SMF Optical Cables

According to different standards, fiber optic cables can be categorized into different classifications. One way is to classify the cable into single-mode fiber (SMF) and multimode fiber (MMF). The comparison between these two types of optical cables can assist you in choosing the most suitable cable for device. This article will compare the two kinds of cables from cable path, distance, precision termination, cost and color. Hope you can find some useful information from the article.

Single Path Vs. Multiple Paths

SMF uses laser light which usually follows a single path through the fiber. MMF takes multiple paths, which may result in a differential mode delay. Each type of fiber can be applied for different equipment. It’s important to know which application is more suitable for practical use. Otherwise, it will not operate at optimal levels.


Short Distances Vs. Long Distances

SMF is used for long distance communication, and MMF is used for distances of 500m or less. Each type is equally as effective when chosen for the proper communication device. Make sure to check the ratings to determine which type is best for your application. The distances should be clearly marked.

Thick Core Size Vs. Thin Core Size

SMF typically has a smaller core size of 8.3 to 10 microns in diameter which is more precise for signal transmission in long distance, while the core size of MMF is much larger than SMF from 50 to100 microns in diameter which is more suitable for short distance transmission owing to the signal distortion. With a thinner core size, SMF is only allowed to carry a single light-wave along a single path, while the thick core size makes MMF able to carry different light-waves along numerous paths without modal dispersion limitation.


Low Cost Vs. High Cost

MMF is typically a lower cost solution than SMF. Limited budget may prompt designers to seek solutions with MMF fiber optic cables. The equipment that’s used for communications over MMF is usually less expensive than SMF. But the typical transmission speed and distance of MMF have limitations of 100 Mbit/s for distances up to 2 km.

Color Differences

MMF and SMF cables can also be distinguished by color. Usually, yellow is used for SMF cable color and orange or aqua is used for MMF cables. It is much easier to distinguish them just by their appearance color.


Other Primary Differences

MMF is typically characterized by having a larger core diameter. In most cases, it’s larger than the wavelength of light it supports. Therefore, MMF has more capacity to gather light than SMF. A larger core size means that designers can create a lower cost electronic device and offer a lower price to the public. Also, by using light-emitting diodes (LEDs) and vertical-cavity surface-emitting lasers (VCSELs), the costs can be driven down even more.


SMF and MMF are two different optic cables which have their own separate application fields. It is terribly wrong for not selecting suitable SMF or MMF patch cables according to the application. Think twice before you are certain that the cable is the best choice for your project. If you want to know more details about SMF and MMF fiber optic cables, FS.COM can solve all your problems.

Talk About QSFP 40G SR4 to 4 SFP 10G SR Transceiver Module

As we know, SFP+ and QSFP+ fiber optic transceiver module and fiber optic cables bring to people a wide variety of high density and low power 40 Gigabit, 10Gigabit, 1 Gigabit, and 100 Megabit Ethernet connectivity options over fiber or copper media.


The example of 40G QSFP transceiver module will bring us to have knowledge of it. In 40G QSFP transceiver module data sheet, we can see that about SFP 40G SR4, cisco thinks, it can be used in a 4 x 10 G mode for interoperability with 10Gbase sr interfaces up to 100m and 150m on OM4 and OM3?cables respectively, in another word, if i connect Nexus 55772UP equipped with “six true QSFP ports” to Nexus 7706 using QSFP 40G SR 4 on the side of 5572UP, and 4 x cisco SFP 10G SR on the side of 7706? Somehow, i think that this is not impossible, but someone thinks that there are fiber optic cables with 40G interface on one side and 4 x 10G SFP (LC connector) on the other side. We can breakout the single 40G port into 4 seperate 10 G ports and use a QSFP to 4 LC breakout cable to link one or more of 10G ports to the 7706.

In fact, Cisco 10Gbase SR4 QSFP Module supports link lengths of 100m and 150m, respectively, on laser optimized OM3 and OM4 multimode fibers. It primarily enables high bandwidth 40G optical links over 12 fiber parallel fiber terminated with MPO/MTP multifiber connectors. It can be used in a 4 x 10G mode for interoperability with 10Gbase sr interfaces up yo 100m and 150m for OM4 and OM3?cables, respectively. The worry free 4 x 10G mode operation is enabled by the optimization of the transmit and receive optical characteristic of the Cisco QSFP 40G SR4 to prevent receiver overload or unnecessary triggering of alarm thresholds on the 10Gbase SR receiver, at the same time being fully interoperable with all standard 40Gbase sr4 interfaces. 4 x 10G connectivity is achieved using an external 12 fiber parallel to 2 fiber duplex breakout cable, which connects the 40GBASE SR4 module to four 10GBASE SR optical interfaces. Cisco QSFP 40G SR4 is optimized to guarantee interoperability with any IEEE 40GBASE SR4 and 10GBASE SR (in 4 X10G modes).

The transceiver consists of parallel electric and optical products along with both transmitter and receiver functions as a single module. It is designed to be compliant to IEEE 802.3-2012 for 40GBase SR4 over 100 m of OM3 multimode fiber at a rate of 41.25 Gbps. This transceiver module has an option to work with four independent 10GBase-SR, IEEE 802.3 Clause 52 Compatible 10 G transceivers through an MPO-to-LC breakout cable (compliant at 100 m over 50 μm OM3 fiber). The transceiver is also fully compliant with the QSFP+ MSA specification SFF-8436 Shown at the Figure.

10gbase sr

To support a good increasing range of 10 and 40 Gigabit Ethernet applications, Fiberstore offers many transceiver types, each optimized for a different media and distance reach (LR4, PLRL4, SR4, XSR4,CR4, CR, SRL, SR, LRL, LR, ER, ZR, and DWDM). Additionally, fiber SFP+ ports also support 3 Gigabit Ethernet SFP transceiver types for single mode fiber, multimode fiber, as well as Cat 5 copper cable.