Blue Superluminescent Diode on c-Plane GaN Beyond Gigahertz Modulation Bandwidth for Visible Light Communication

Recently, GaN light-emitting diode (LED) and laser-diode (LD) have recently been developed for solid-state lighting (SSL) and visible light communication (VLC) [1, 2]. Superluminescent diode (SLD), which operates in the amplified spontaneous emission (ASE) mode offers further niche in SSL and VLC applications. The ASE (superluminescent) occurs when the optical feedback is suppressed, and thus inhibiting the onset of lasing. SLD offers speckles-free emission that is associated with LD, as well as exhibits shorter carrier lifetime since it operates in the ASE regime. The ASE results in a high modulation bandwidth and high data rate [3], as compared to LED, which operates in the spontaneous emission regime. In our previous work, we have demonstrated 560 MHz [4] and 800 MHz [3] of modulation bandwidth for semipolar-based SLDs. However, the expensive production cost of those substrates prevents them from wide-availability. Thus, here, we demonstrate a c-plane GaN-based SLD emitting at 442 nm with beyond GHz of bandwidth for simultaneous dual SSL-VLC technology.