Monolithically grown superluminescent diodes on germanium and silicon substrates

We demonstrate the first InAs/GaAs quantum-dot (QD) superluminescent diode (SLD) monolithically grown on both Ge and Si substrates by molecular beam epitaxy. The QD SLDs on Ge substrates exhibit a 3 dB emission bandwidth of ~60 nm with output power of 27 mW at room temperature, and operates up to 100 ^°C. We also report the first QD SLD monolithically grown on a Si substrate. A two-section ridge structure has been used to achieve a close-to-Gaussian emission spectrum of 114 nm centered at ~1255 nm wavelength, with a maximum output power of 2.6 mW at room temperature.