The LED1550E from Thorlabs Inc is a Near-Infrared (NIR) LED that operates at a wavelength of 1500 nm. It delivers an optical power of 2 mW and has a wavelength tolerance of ±50 nm. This LED has a full width at half maximum (FWHM) of 100 nm and half viewing angle of 15 deg. It has a forward voltage of 1.2 V and rise or fall time of 10 ns. This LED has a reverse voltage of 5 V and dissipates 120 mW of power. It is composed of heterostructures (HS) grown on an InGaAsP substrate and encapsulated in a round clear epoxy casing that measures 36 mm x 5.9 mm x 5 mm.