The attached plot shows an example of the impact of DAS tuning on carrier contrast defect. Carrier contrast defect is computed as the ratio of calibrated B4 power to calibrated B1p carrier power, where the fraction of carrier in B1p is extracted from the B1p phase camera. Data refer to the DAS tuning done after WE mirror replacement, and span from June 10 to August 17 2025, i.e. after the ETM RH tuning was over.
Here's another example dating back to input laser changes in early 2024, when a 50% improvement in contrast defect follwed a tuning of WI DAS power.
