The SLD4B-1550-1 from LD4B is a Superluminescent Diode (SLD) that has a mean wavelength of 1550 nm. It delivers an output power of up to 1 mW and has a spectral width of 40 nm. This SLD has a spectral modulation of 1 % and wavelength-temperature coefficient of 0.7 nm/^oC. It has a minimum cut-off frequency of 150 MHz (at -3 dB) and polarization extinction ratio of 17 dB. This continuous wave SLD requires a DC supply voltage of 1.3 V and has a built-in monitor photodiode (PD) with a monitor current of 0.1 mA. It is available in coaxial, coaxial with bracket, 14-pin DIL, or 14-pin BTF hermetic packages.