The Difference Between BiDi Single Fiber Optical Transceiver and Dual Fiber Optical Transceiver
What is a Single Fiber Bidirectional Optical Transceiver?
The BiDi optical module has a compact structure and is mainly used in the field of optical communication, including telecommunications and two-way data communication. Single fiber bidirectional, or BiDi, means that optical signals in both directions can be transmitted and received simultaneously in a single fiber, just like the front and back lanes separated by isolation bands on the road, and the vehicles on both sides are in their respective lanes. Drive without interfering with each other. The conventional optical fiber transmission is single-fiber unidirectional, so two optical fibers are needed to realize bidirectional communication.
Working Principle of BIDI Single Fiber Bidirectional Optical Transceiver
BIDI single-fiber bidirectional optical modules need to transmit and receive optical signals in two directions at the same time, and different optical wavelengths need to be used in the transmit and receive directions. Generally, an optical module has two ports, a transmitting port and a receiving port. The single-fiber bidirectional optical module has only one port, which is filtered by the filter in the optical module, and simultaneously completes the transmission of one wavelength optical signal and the reception of another wavelength optical signal, or vice versa.
For example, the local end emits an optical signal of 1310nm while receiving an optical signal of 1550nm. The opposite end uses the opposite wavelength to that of the local end, that is, it emits 1550nm optical signals and receives 1310nm optical signals. Therefore, the module must be used in pairs at both ends of the link. The commonly used wavelengths of single-fiber bidirectional optical modules are 1310nm/1490nm and 1510nm/1590nm.
The one-way two-way transceiver module integrates the MQW-TO-LD light source, TO-PIN-TIA (transimpedance amplifier) detector, beam splitter, optical fiber and other components with coaxial coupling technology.
Our conventional module is dual fiber, that is, there are two fiber jacks, as shown in the figure:
Using WDM technology, different center wavelengths are used in the sending and receiving directions. Realize a fiber to transmit optical signals in both directions. Generally, the optical module has two ports, TX is the transmitting port, and RX is the receiving port;
The BIDI optical module has only one port, which is filtered by the filter in the optical module, and simultaneously completes the transmission of 1310nm optical signals and the reception of 1550nm optical signals, or vice versa. Therefore, the module must be used in pairs, and its biggest advantage is to save fiber resources.
The commonly used wavelengths of BIDI optical modules are 1310nm/1550nm; 1310nm/1490nm; 1510nm/1590nm. Of course, CWDM and DWDM also have single-fiber bidirectional
The dual-fiber bidirectional and BIDI optical modules have the same practical effect. The only difference is that customers can choose single-fiber or dual-dual fiber according to their needs.
Single-fiber bidirectional optical modules are more expensive, but can save one fiber resource, which is a better choice for users with insufficient fiber resources.
The dual-fiber bidirectional optical module is relatively cheap, but one more fiber is needed. If the fiber resources are sufficient, you can choose a dual-fiber optical module.
Why Choose BiDi Optical Transceiver?
BiDi optical modules, such as SFP+ BiDi optical modules or SFP BiDi optical modules, have the most obvious advantage in that they can reduce the number of ports on the optical fiber patch cord panel, save the cost of optical fiber cabling infrastructure, and can also reduce cabling space, which helps optical fibers. Management, and reduce the number of fibers needed to use.
The price of BiDi optical modules (WDM optical modules) is higher than that of traditional dual-fiber bidirectional optical modules, but the number of optical fibers required by BiDi optical modules per unit transmission distance has been reduced by half. For many network lines, the cost savings of using fewer optical fibers far exceeds the cost of purchasing BiDi optical modules.
Application of BiDi single fiber bidirectional optical module
Single-fiber two-way communication is usually used for user access networks to complete image, data, and voice communications at low cost.