Table 1.

List of notations and measured values for the efficiencies corresponding to the different paths involved in the experiment

Notation	Path	x	y	z	s	Efficiency
${\eta }_A^s$	x → switch → DA	1			1	0.315 ± 0.008
${\eta }_B^y$	x → y → DB	0	0			0.303 ± 0.008
${\eta }_A^{V_1}$	$x\to \mathrm{switch}\to z\to D_{V_1}$	1		1	0	0.231 ± 0.008
${\eta }_A^{V_2}$	$x\to \mathrm{switch}\to z\to D_{V_2}$	1		0	0	0.219 ± 0.008
${\eta }_B^{V_1}$	$x\to y\to z\to D_{V_1}$	0	1	0		0.184 ± 0.008
${\eta }_B^{V_2}$	$x\to y\to z\to D_{V_2}$	0	1	1		0.175 ± 0.008

The paths are described by the PBSs (labelled by the corresponding reflectivities) and/or the switch they go through, as well as the detector at the end of the path. We also list the values of x, y, z, and the state of the switch s, required to measure these efficiencies. Values are given for VOAs set at 0 dB.