What is inside an optical transceiver?
Playing a big role on connecting different network devices to transmit and receive data, optical transceivers are very essential in the optical communication system. There is lots of information available to introduce their types, features and parameters, but we still know little about the internal elements. What is inside an optical transceiver? After viewing the assembly process and having conversations with experienced workers in the workshop, I am writing this article to answer this question.
Brief to make a definition, the main elements inside an optical transceiver can be generally divided into three parts: the externally housing, optoelectronic devices and PCBA.
![The Internal Components of Optical Transceiver]( "The Internal Components of Optical Transceiver")
What are the optoelectronic devices?
When it comes to the core component of an optical transceiver, it must be the optoelectronic devices. For general transceivers, there are two widely used types of optoelectronic devices called TOSA and ROSA. The brief introductions of these two devices are followed.
l What is TOSA?
One of major functions of an optical transceiver is to make a si![The Internal Components of Optical Transceiver]( "The Internal Components of Optical Transceiver")
gnal conversion. TOSA(Transmitter Optical Sub Assembly) is inside the transmit side of SFP ports with the function of converting the electrical signal into the optical signal, consisting of light source (light emitting diode or laser diode), optical interface, monitor photodiode, metal and/or plastic housing, and electrical interface. However, there may be other components in order to meet the requirements of different transmission distance and applications.
l What is ROSA?
Accordingly, ROSA(Receiver Optical Sub Assembly) is inside the receive side of SFP ports, and responsible for converting the optical signal into the electrical signal. A typical ROSA contains and optical interface, a photodiode(PD), plastic and/or metal housing, and an electrical interface. Undoubtedly ROSA, like TOSA, maybe have other components according to specific requirements and applications of transceivers.
l What is BOSA?
TOSA and ROSA are important components in the uni-directional transceivers (traditional transceivers) which transmit on one fiber optic strand and receive on the other fiber optic strand. With the development of the bidirectional technology, optical transceivers have realized the function of supporting two wavelengths on a fiber. This kind of optical transceiver is called Bidi transceiver. BOSA, which is short for Bi-Directional Optical Sub Assembly, is applied for the Bidi transceiver and comes integrated with a WDM filter, ROSA, and a TOSA.
What is PCBA?
The term PCBA refers to Printed Circuit Board Assembly. Surface Mounted Technology (SMT) and Dual In-line Package (DIP) are both common methods used in PCB Assembly. Its major functions is to protect integrated circuits and other electronic devices as a way to quality assurance. Many people maybe feel confused about PCBA and PCB. What is the difference of these two terms? PCB, which means Printed Circuit Board, is a bare board. In other words, it is used as a carrier for electronic components. And PCBA is a completed assembly, that is to say, there are other parts that are assembled onto the PCBA apart from PCB.
Conclusion
This writing aims to briefly introduce the internal of an optical transceiver, including TOSA, ROSA, BOSA and PCBA. Much more useful and detailed information is worth exploring and studying. If you want to know more about the related information, please contact us. BEIHAI’s technical team will try the best to give you support. We are professional and reliable. Sincerely hope to become your loyal partner.