Views: 399 Author: Anna Publish Time: 2025-07-15 Origin: Site
First of all, we need to understand the various parameters of optical modules, of which the three most important ones are central wavelength, transmission distance, and transmission rate. The main differences between optical modules are also reflected in these points.
The unit of central wavelength is nanometer (nm). There are currently three main types:
850nm (MM, multi-mode, low cost but short transmission distance, generally only 500m);
1310nm (SM, single-mode, large loss during transmission but small dispersion, generally used for transmission within 40km);
1550nm (SM, single-mode, small loss during transmission but large dispersion, generally used for long-distance transmission of more than 40km, the longest can be directly transmitted without relaying 120km).
The transmission distance refers to the distance that the optical signal can be directly transmitted without relaying and amplification, in kilometers (also called kilometers, km). Optical modules generally have the following specifications: multi-mode 550m, single-mode 15km, 40km, 80km and 120km, etc.
The transmission rate refers to the number of bits (bits) of data transmitted per second, in bps. The transmission rate is as low as 100M and as high as 100Gbps. The commonly used rates are 155Mbps, 1.25Gbps, 2.5Gbps and 10Gbps. The transmission rate is generally downward. In addition, in the optical fiber storage system (SAN), the optical module has three rates of 2Gbps, 4Gbps and 8Gbps.
After understanding the above three optical module parameters, do you have a preliminary understanding of the optical module? If you want to know more, let's take a look at the other parameters of the optical module!
Both of them mainly affect the transmission distance of the optical module. Generally, the link loss of 1310nm optical module is calculated at 0.35dBm/km, and the link loss of 1550nm optical module is calculated at 0.20dBm/km. The calculation of dispersion value is very complicated and is generally only used for reference;
These two parameters are mainly used to define the transmission distance of the product. Optical modules with different wavelengths, transmission rates and transmission distances have different light transmission power and receiving sensitivity;
Currently, the most commonly used lasers are FP and DFB. The semiconductor materials and resonant cavity structures of the two are different. DFB lasers are expensive and are mostly used for optical modules with a transmission distance greater than 40km; while FP lasers are cheap and are generally used for optical modules with a transmission distance within 40km.
SFP optical modules are all LC interfaces, GBIC optical modules are all SC interfaces, and other interfaces include FC and ST, etc.
International unified standard, 7×24 hours of uninterrupted work for 50,000 hours (equivalent to 5 years);
Working temperature: 0~+70℃; Storage temperature: -45~+80℃; Working voltage: 3.3V; Working level: TTL.
SFP (Small form-factor pluggable) means small pluggable. It is a pluggable module that can support Gigabit Ethernet, SONET, Fiber Channel and other communication standards and is inserted into the SFP port of the switch. The SFP specification is based on IEEE802.3 and SFF-8472, which can support speeds up to 4.25 Gbps. Due to its smaller size, SFP replaced the previously common Gigabit Interface Converter (GBIC), so it is also called mini GBIC SFP. By selecting SFP modules with different wavelengths and ports, the same electrical port on the switch can be connected to optical fibers with different connectors and different wavelengths.
Since SFP only supports a transmission rate of 4Gbps, which cannot meet people's increasing demand for network speed, SFP+ was born in this context. The maximum transmission rate of SFP+ can reach 10 Gbps. In fact, SFP+ is an enhanced version of SFP. The SFP+ specification is based on SFF-8431. With its small size and easy use, it replaced the XENPAK and XFP modules that were widely used in the early 10 Gigabit Ethernet and became the most popular optical module in 10 Gigabit Ethernet.
After analyzing the above definitions of SFP and SFP+, it can be concluded that the main difference between SFP and SFP+ is the transmission rate. And due to the different data rates, the applications and transmission distances are also different.
After understanding the above optical module knowledge, I believe that everyone's understanding of optical modules has been greatly improved. The transmission and path of YXFiber optical module series products meet the user's requirements for high performance, low cost, support for all major interfaces and product appearance. It mainly includes SFP/SFP+ optical modules and XFP optical modules, which have very wide applications in the field of optical communications and are fully compatible with many brands of equipment, such as CIsco, Huawei, Juniper, etc.