Optical transceivers are at the core of fiber optic networks and must meet the highest quality standards. Military and space applications require more rigorous testing. Our company covers the various tests for transceivers deployed in non-rugged environments. Given below are the recommended qualification tests that an optic has to pass before deployment in the field.
DVT (Design Verification Testing) is the most important qualification test that transceivers undergo regardless of application. The 5- corner test is performed at the five combinations given by max-min values of temperature and input voltage, which are the most important external variables. All transceiver parameters are tested over the different combinations of temperature and voltage.
Firmware and critical timings: Critical timings are measured and compared to MSA and I2C specifications to confirm accuracy. Transceiver firmware upgrades are a frequent occurrence, especially in higher data rate modules. Some applications like data centers require firmware upgrades to be performed with the modules in the rack. This feature may not be as critical for other applications.
Sub-component qualification: Certain applications require stringent sub-component qualification. In some cases, we provide TOSA and ROSA DVT information to customers for qualification.
Mechanical Tests: Military and space applications require running the transceivers through rigorous mechanical tests, but tests like hot pluggability and accelerated aging tests are required for all applications. 3 months or 2000 hours is the industry accepted timeframe to run the aging test without failure.
Management: Generally, the Alarm/Warning threshold and DDM values are accurate if the transceivers have been calibrated correctly. Management tests also include EEPROM verification.
Environmental and Thermal: Transceivers that are deployed in harsh environments need to operate at a wider range. Safety, reliability, and quality standards: These are the typical standards that an optical transceiver has to comply with.
Inter-operability: This is an important test to run with a group of 3 to 4 different suppliers to ensure that the module communicates well with other manufacturer’s modules.
Electromagnetic Tests: EMI testing can get expensive, so this may not be required for indoor applications. EMS testing is required if the modules are installed near other high frequency equipment. ESD testing is typically required for all applications.
Packaging and labeling: Transceiver labels and packaging have to conform to customer specs. The most widely seen transceiver failure modes are inconsistent EEPROM coding and labeling.
Apart from the above, most common failures are Rx LOS, Tx eye mask, Tx jitters and Rx sensitivity. To avoid service disruptions and network downtime, it is key to purchase high quality, proven transceivers.