VCSELS (vertical-cavity surface-emitting lasers) have a smaller beam angle than LEDs (Light-Emitting Diodes) ; in result VCSEL has more optical power that can be used with the same amount of current or less, resulting in longer-range interconnections. LEDs have their data rate limitation of 622 Mbit/s  and as they can’t be turned on and off quickly enough they are unable to support high bandwidth applications. VCSELs can be modulated at speeds over 10 Gbps and are used in high-speed applications.