Wavelength stability in a hybrid photonic crystal laser through controlled nonlinear absorptive heating in the reflector

This work was supported by the Science Foundation Ireland under Grants SFI12/RC/2276 and 16/ERCS/3838, Engineering and Physical Sciences Research Council (EPSRC) (doctoral grant EP/L505079/1 and equipment grant EP/L017008/1); European Research Council (ERC) (Starting Grant 337508); and Scottish Enterprise.The need for miniaturized, fully integrated semiconductor lasers has stimulated significant research efforts into realizing unconventional configurations that can meet the performance requirements of a large spectrum of applications, ranging from communication systems to sensing. We demonstrate a hybrid, silicon photonics-compatible photonic crystal (PhC) laser architecture that can be used to implement cost-effective, high-capacity light sources, with high side-mode suppression ratio and milliwatt output output powers. The emitted wavelength is set and controlled by a silicon PhC cavity-based reflective filter with the gain provided by a III–V-based reflective semiconductor optical amplifier (RSOA). The high power density in the laser cavity results in a significant enhancement of the nonlinear absorption in silicon in the high Q-factor PhC resonator. The heat generated in this manner creates a tuning effect in the wavelength-selective element, which can be used to offset external temperature fluctuations without the use of active cooling. Our approach is fully compatible with existing fabrication and integration technologies, providing a practical route to integrated lasing in wavelength-sensitive schemes.Publisher PDFPeer reviewe