Tapered Multi-Section Superluminescent Diode with Tunable Spectral Asymmetry between Narrow and Wide Facet Outputs

Combining the output of two or more separate, distinct superluminescent diodes (SLDs) via spectral multiplexing has the potential to produce very wide optical spectra which could prove beneficial in imaging applications1. Likewise, the implementation of a multi-section contact layout also allows for optimization of the spectral bandwidth and output power through the independent tuning of the current density in each section2. Here, we present the first comparative investigation of the output from both facets of a tapered multi-section SLD. A significant spectral asymmetry between the output of both facets was observed and was found to be widely tunable through the variation of the biasing conditions in both sections of the device. These results highlight an as yet untapped extra degree of freedom in multi-section superluminescent diodes which could be exploited to engineer the spectral bandwidth of such devices through the multiplexing of both outputs of a single device.