Record-high power spectral density CW tapered quantum-dot superluminescent diode

Superluminescent diodes (SLDs) with high power spectral density present an appealing low cost, small footprint and relatively simple alternative to supercontinuum sources for spectroscopy applications that do not require extremely broad optical spectra. Numerous approaches have been used to optimise the performance of SLDs in this respect. Here, we present a superluminescent diode under CW operation with a record-high power spectral density owing to its chirped quantum-dot active region, two-section contact layout and long tapered waveguide geometry.