Table 1.

The specification of the IR LED (SFH 4544 Infrared Emitter 940 nm by OSRAM Opto Semiconductors) used in experiments.

No	Parameter	Symbol	Values	Unit
1	Centroid wavelength	${\lambda }_{\mathrm{centroid}}$	940	nm
2	Half angle	$\phi$	±10	deg
3	Forward voltage	$V_F$	1.6	V
4	Forward current	$I_F$	100	mA
5	Total radiant flux	$\mathsf{\Phi }$	75	mW