Industry Information

With the development of network and the progress of technology, many optical fiber component manufacturers appear in the market, trying to seize the share of the network world. Since these manufacturers produce various components, their goal is to manufacture high-quality and mutually compatible components so that customers can mix various components from different manufacturers. This is mainly due to financial problems, because many data centers have been looking for cost-effective solutions to implement in their networks.

Optical transceiver is an important part of optical network. They are converting and driving optical cables through optical cables. They consist of two main parts: transmitter and receiver. In terms of maintenance and troubleshooting, it is very important to be able to predict, test and find out where problems may or have occurred. Sometimes, if the connection does not reach the expected bit error rate, at first glance, we will not be able to determine which part of the connection caused the problem. It could be a cable, a transceiver, a receiver, or both. Generally, the specification should ensure that any receiver will work normally with any worst-case transmitter, and vice versa, and any transmitter will provide a signal of sufficient quality to be picked up by any worst-case receiver. The worst-case criterion is usually the hardest part to define. However, there are usually four steps to test the transmitter and receiver parts of the transceiver.

When testing the transmitter part, the test includes testing the wavelength and shape of the output signal. There are two steps to test the transmitter:

The optical output of the transmitter must be tested with the help of multiple optical quality indicators, such as template test, optical modulation amplitude (OMA) and extinction ratio. Test with eye pattern template test, which is a common method to view the transmitter waveform and provide information about the overall transmitter performance. In the eye diagram, the combination of all data patterns is superimposed on a common time axis, and the width is usually less than two bit periods. The test receiving part is a more complex part of the process, but there are also two test steps:

The first part of the test is to confirm that the receiver can receive signals of poor quality and convert them. This is done by sending poor quality light to the receiver. Since this is an optical signal, it must be calibrated using jitter and optical power measurement. Another part of the test is to test the electrical input of the receiver. In this step, three types of tests must be performed: eye pattern template test to ensure a large enough eye pattern opening, jitter test to test some types of jitter and jitter tolerance test, and test the ability of the receiver to track jitter within its loop bandwidth.