LIV and spectral test of laser diode bars and chips
Quality control is an important step in the production process of laser diode chips and laser diode bars. To test if all functional components are meeting the demanding specifications of the market the components can be tested with an automatic test system from ficonTEC’s test line. Complete bars are picked up by a vacuum pick up tool (PUT) and set down on a stationary gold coated chuck. For the testing process a probe head is aligned to the single die (emitter) or the full bar is contacted completely in one time. The laser is driven by either a DC current source or in most of the cases with pulse-mode testing with a current pulser with very short pulse which minimize power dissipation and avoid destructive self-heating length.
The optical power is measured either with a large area detector, an integrating sphere or a photodetector at the end of an optical fiber depending on the devices requirements. The characteristical laser parameters are measured by running an LIV or a DC sweep. Parallel to the optical power the optical output spectrum and near and far field characteristics can be measured.
All accumulated data is written to a SQL Database which allows the machine user perfect statistical analysis of the data and feedback this information back to production for e.g. yield improvements. The systems allow full component tracking and sorting if they are equipped with a handling system.