Abstract: A method and structure are provided for testing photonic circuits with integrated optical mixers having idle ports. A test port is provided for coupling test light into one or more idle ports of the mixer. Light exiting output ports of the mixer may be measured with photodetectors. Phase errors of optical hybrids may be determined by using waveguides of different lengths to inject test light into two input ports of the mixer and scanning the test wavelength. The method and structure may be used for on-wafer and off-wafer measurements of integrated photonic circuits implementing coherent optical receivers.

Abstract: Otherwise-unused metal pads are utilized for mechanically marking an identification number on each chip in each reticle of each semiconductor wafer. A chip-specific marking pattern is scribed into selected metal pads using a standard commercial wafer probe controlled by a custom-built controller to direct the probe or probe stage to implement the pattern. Visual inspection (manual and automated) may then be used for die identification based on the probe-marked pattern, including incorporating the visual inspection of these pads into the product building process.

Abstract: Otherwise-unused metal pads are utilized for mechanically marking an identification number on each chip in each reticle of each semiconductor wafer. A chip-specific marking pattern is scribed into selected metal pads using a standard commercial wafer probe controlled by a custom-built controller to direct the probe or probe stage to implement the pattern. Visual inspection (manual and automated) may then be used for die identification based on the probe-marked pattern, including incorporating the visual inspection of these pads into the product building process.