Optical probing using the Schlumberger IDS-2000 and other infrared-based analysis techniques have proved to be critical in the debug and analysis of flip-chip-packaged microprocessors. During probing, processors are operating with test patterns that generate a large amount of power. This article demonstrates a method for dissipating the generated heat based on a diamond window-based transparent heat spreader. This method controls the microprocessor temperature to a high degree of stability, and reduces thermal gradients across the die. Waveform results are excellent, and the transparent heat spreader provides a path for optical probing to be applied to the entire range of integrated circuit applications. The discussion covers cooling system requirements, and standard configuration specifications, and shows how the transparent heat spreader technique is effective for probing high power microprocessors.