Table 1.

RI of sensor materials at different wavelengths.

RI	${\mathit{\lambda }}_1 (532.0 \mathbf{nm})$	${\mathit{\lambda }}_2 (632.8 \mathbf{nm})$	${\mathit{\lambda }}_3 (780.0 \mathbf{nm})$	${\mathit{\lambda }}_4 (1152 \mathbf{nm})$
BK7 [34]	1.5195	1.5151	1.5112	1.5055
Au [34,66]	0.0990 + 2.9952i	0.1377 + 3.6183i	0.2063 + 4.5133i	0.4417 + 6.7308i
PtSe2 [34,67]	2.5917 + 1.1332i	2.9029 + 0.8905i	2.8229 + 0.5277i	2.7986 + 0.2878i
Graphene [34,68]	3 + 0.9658i	3 + 1.1487i	3 + 1.4160i	3 + 2.0913i