a diffractive optical element (DOE) disposed in the PIC, the DOE having a focal point of absolute maximum reflection at location having coordinates in three-dimensions above the PIC;

an optical waveguide probe;

an optical source adapted to provide light through the optical waveguide probe and incident on the DOE, wherein the DOE reflects and focuses light back to the optical waveguide probe;

a power meter adapted to receive at least a portion of the light reflected and focused at the focal point of maximum above the PIC;

a motorized positioner adapted to move in optical waveguide probe in the three-dimensions above the PIC; and

a controller comprising a processor and a memory that stores instructions, which when executed by the processor, causes the processor to: control the motorized positioner to: move the optical waveguide probe in a first plane to locate a first maximum reflection in the first plane; move the optical waveguide probe to a second plane, and move the optical waveguide probe in the second plane to locate a second maximum reflection in the second plane; move the optical waveguide probe to other planes until the absolute maximum reflection is located.