Light metrology of microLED arrays for optical interconnects

MicroLED arrays are attracting growing interest for optical interconnects, with several companies investigating their use in co-packaged optics (CPO) for high-speed, low-power data-center applications. Their optical characterization can build on metrology developed for microLED displays in augmented-reality (AR) devices. However, optical interconnects require particular emphasis on radiometric quantities rather than photometric metrics. This presentation demonstrates how microLED emitters can be characterized at both wafer and assembled-array levels using display- and light-metrology equipment. The measurement approaches provide information on optical power, emission spectra, radiant efficiency, and spatial emission distributions. The presentation illustrates the suitability of established display-characterization methods for evaluating microLED sources intended for optical-interconnect applications.