Abstract: A monitoring system for a multi-laser module includes detectors corresponding to each laser and situated to receive a portion of the associated laser beam uncombined with other beams. Laser characteristics are measured and stored, and in operation are used to identify device failures. A comparator receives a reference value and compares the reference value with a current operational value. If the current value is less that the reference value, a possible failure is indicated. Signal cross-coupling among the detectors is also used to identify undesirable scattering that can be associated with surface contamination or device failure.

Abstract: A monitoring system for a multi-laser module includes detectors corresponding to each laser and situated to receive a portion of the associated laser beam uncombined with other beams. Laser characteristics are measured and stored, and in operation are used to identify device failures. A comparator receives a reference value and compares the reference value with a current operational value. If the current value is less that the reference value, a possible failure is indicated. Signal cross-coupling among the detectors is also used to identify undesirable scattering that can be associated with surface contamination or device failure.

Abstract: An alignment technique can be used to align a semiconductor wafer during wafer testing. During a gross alignment process, a bump pattern on the wafer surface is located. Based on a known relative location relationship between the bump pattern and a fiducial on the wafer surface, the fiducial can be located. The wafer can then be initially aligned. During a fine alignment process, the bump pattern technique can again be used and additional alignment performed. Blurring can be used so that features other than bumps become less discernable.