Measurement of the splitting ratio of the three directional couplers with 7.5 mm interaction length forming the 4T-nuller (three plots from the left) and for the Y-junction photometric tap. The error bars correspond to three times the standard deviation obtained from four independent measurements. In the last plot, the gray curves depict one of the four Y-junctions in the characterized 4T-nuller, while the green curves show the properties of the targeted 80/20 splitter, which will be implemented in a future version.