Addressing Reliability in a Non-Hermetic Laser Package

August 2, 2019

Data transmission rates and performance demands are both increasing, and cooled non-hermetic laser packages are one way of cutting costs while meeting the performance requirements of those demands. But it’s not enough to invest in a non-hermetic solution that can meet demand for just a short lifespan. Optical component manufacturers need to build laser packages for maximum survivability to ensure long-term cost of ownership reductions.

Attaining Reliability and Performance

Your thermoelectric cooler (TEC) is one component that needs to satisfy reliability targets in order to protect against failure and ensure that performance demands are met. In many applications, “going uncooled” is no longer a realistic option, but cooled non-hermetic packages present a number of environmental challenges that need to be accounted for in the design process.

Condensation, humidity, corrosion and ice are all factors that can degrade TOSA performance, by creating electrical shorting pathways and interrupting the coupling of the laser light emission to the fiber. If these problems aren’t addressed, laser slope efficiency will degrade, coupling losses will increase and data transmission rates will slow. Ultimately, the usable lifetime of your laser package will also decline, inherently raising cost of ownership and requiring additional investments in equipment replacement.

Testing for Reliability

It’s not enough to rely on the standard Telcordia reliability specs which assume ideal, non-condensing conditions. To make sure your cooled, non-hermetic laser product is designed to withstand tough conditions found in real-world use, you need to relate your accelerated reliability test (e.g. 85°C/85% humidity) to include the most common use cases where condensation occurs.

  • Temporary sub-dew point operation: There will be cases where your laser package may operate below the dew point, which can lead to condensation that affects TOSA performance. The most likely situations are cold starts, which can add up over time even if the state only persists for five minutes once per day, or situations where there is unexpected climate control failure. If your TEC cannot withstand these conditions, its lifetime will be significantly shorter than expectations.

Phononic’s ReefTEC™ platform is designed to perform in real-world environments where condensation occurs. Unlike solutions that utilize edge sealants or coatings, our ReefTEC™ platform has been completely redesigned from the ground up, in order to solve for the root cause of failure in condensing situations. It was proven to deliver survivability equal to 5 times that of a hermetic platform.

In addition to significantly better survivability, ReefTEC™ also enables up to 50% savings on TOSA package cost. Want to see how much you could save? Try our online calculator.