Sales growth outpaces optical testing capacity
Production test equipment for optical components has lagged behind the rapid sales growth of fiber-optic communications devices. If sales of dense wavelength division multiplexing (DWDM) fiber-optic communication systems are to continue at the present rate, production costs and component prices must drop substantially.
One manufacturer predicted that prices need to drop by as much as 40%.
This is the situation facing manufacturers of LDMs, a critical element of DWDM communication systems. Testing is a major cost element in LDM production, due to the high value added during manufacturing. This makes it prudent to test LDMs after each major production step.
Those steps include the wafer processing, finished laser diode chip, chip on carrier, laser mounted on its thermoelectric cooler, addition of fiber coupling, completed module, and post-burn-in steps.
Furthermore, production testing requires copious data collection during light current voltage sweeps to capture LDM characteristics such as laser diode drive current, forward voltage drop, and light output. Often, these tests occur at multiple operating temperatures.
With rapidly escalating demand, manufacturers have frequently found it expedient to transfer lab test instruments to the production floor. While this is a quick solution, it usually does not provide the highest productivity.
Of course, LDM manufacturers need sensitive instruments that provide highly accurate measurements, but they must also provide much higher throughput than lab instruments. Production test instruments need features that address these realities.
The problem may be over.